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* Merge tag 'riscv-for-linus-5.0-rc5' of ↵Linus Torvalds2019-02-021-5/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux Pull RISC-V fixes from Palmer Dabbelt: "This contains a handful of mostly-independent patches: - make our port respect TIF_NEED_RESCHED, which fixes CONFIG_PREEMPT=y kernels - fix double-put of OF nodes - fix a misspelling of target in our Kconfig - generic PCIe is enabled in our defconfig - fix our SBI early console to properly handle line endings - fix max_low_pfn being counted in PFNs - a change to TASK_UNMAPPED_BASE to match what other arches do This has passed my standard 'boot Fedora' flow" * tag 'riscv-for-linus-5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: riscv: Adjust mmap base address at a third of task size riscv: fixup max_low_pfn with PFN_DOWN. tty/serial: use uart_console_write in the RISC-V SBL early console RISC-V: defconfig: Add CRYPTO_DEV_VIRTIO=y RISC-V: defconfig: Enable Generic PCIE by default RISC-V: defconfig: Move CONFIG_PCI{,E_XILINX} RISC-V: Kconfig: fix spelling mistake "traget" -> "target" RISC-V: asm/page.h: fix spelling mistake "CONFIG_64BITS" -> "CONFIG_64BIT" RISC-V: fix bad use of of_node_put RISC-V: Add _TIF_NEED_RESCHED check for kernel thread when CONFIG_PREEMPT=y
| * tty/serial: use uart_console_write in the RISC-V SBL early consoleAndreas Schwab2019-01-241-5/+8
| | | | | | | | | | | | | | | | | | | | This enables proper NLCR processing. Suggested-by: Anup Patel <anup@brainfault.org> Signed-off-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
* | serial: fsl_lpuart: fix maximum acceptable baud rate with over-samplingTomonori Sakita2019-01-221-1/+1
| | | | | | | | | | | | | | | | Using over-sampling ratio, lpuart can accept baud rate upto uartclk / 4. Signed-off-by: Tomonori Sakita <tomonori.sakita@sord.co.jp> Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty: serial: qcom_geni_serial: Allow mctrl when flow control is disabledMatthias Kaehlcke2019-01-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | The geni set/get_mctrl() functions currently do nothing unless hardware flow control is enabled. Remove this arbitrary limitation. Suggested-by: Johan Hovold <johan@kernel.org> Fixes: 8a8a66a1a18a ("tty: serial: qcom_geni_serial: Add support for flow control") Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty: Handle problem if line discipline does not have receive_bufGreg Kroah-Hartman2019-01-211-1/+2
| | | | | | | | | | | | | | | | | | | | Some tty line disciplines do not have a receive buf callback, so properly check for that before calling it. If they do not have this callback, just eat the character quietly, as we can't fail this call. Reported-by: Jann Horn <jannh@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: invoke notifier on screen size changeNicolas Pitre2019-01-181-0/+1
| | | | | | | | | | | | | | | | | | User space using poll() on /dev/vcs devices are not awaken when a screen size change occurs. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: always call notifier with the console lock heldNicolas Pitre2019-01-181-1/+1
| | | | | | | | | | | | | | | | | | Every invocation of notify_write() and notify_update() is performed under the console lock, except for one case. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: make vt_console_print() compatible with the unicode screen bufferNicolas Pitre2019-01-181-32/+15Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kernel messages are printed to the console, they appear blank on the unicode screen. This is because vt_console_print() is lacking a call to vc_uniscr_putc(). However the later function assumes vc->vc_x is always up to date when called, which is not the case here as vt_console_print() uses it to mark the beginning of the display update. This patch reworks (and simplifies) vt_console_print() so that vc->vc_x is always valid and keeps the start of display update in a local variable instead, which finally allows for adding the missing vc_uniscr_putc() call. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty/n_hdlc: fix __might_sleep warningPaul Fulghum2019-01-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after calling copy_to_user. This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 Signed-off-by: Paul Fulghum <paulkf@microgate.com> Reported-by: syzbot <syzbot+c244af085a0159d22879@syzkaller.appspotmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: stable <stable@vger.kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: 8250: Fix serial8250 initialization crashHe Zhe2019-01-181-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The initialization code of interrupt backoff work might reference NULL pointer and cause the following crash, if no port was found. [ 10.017727] CPU 0 Unable to handle kernel paging request at virtual address 000001b0, epc == 807088e0, ra == 8070863c ---- snip ---- [ 11.704470] [<807088e0>] serial8250_register_8250_port+0x318/0x4ac [ 11.747251] [<80708d74>] serial8250_probe+0x148/0x1c0 [ 11.789301] [<80728450>] platform_drv_probe+0x40/0x94 [ 11.830515] [<807264f8>] really_probe+0xf8/0x318 [ 11.870876] [<80726b7c>] __driver_attach+0x110/0x12c [ 11.910960] [<80724374>] bus_for_each_dev+0x78/0xcc [ 11.951134] [<80725958>] bus_add_driver+0x200/0x234 [ 11.989756] [<807273d8>] driver_register+0x84/0x148 [ 12.029832] [<80d72f84>] serial8250_init+0x138/0x198 [ 12.070447] [<80100e6c>] do_one_initcall+0x5c/0x2a0 [ 12.110104] [<80d3a208>] kernel_init_freeable+0x370/0x484 [ 12.150722] [<80a49420>] kernel_init+0x10/0xf8 [ 12.191517] [<8010756c>] ret_from_kernel_thread+0x14/0x1c This patch makes sure the initialization code can be reached only if a port is found. Fixes: 6d7f677a2afa ("serial: 8250: Rate limit serial port rx interrupts during input overruns") Signed-off-by: He Zhe <zhe.he@windriver.com> Reviewed-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | uart: Fix crash in uart_write and uart_put_charSamir Virmani2019-01-181-4/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We were experiencing a crash similar to the one reported as part of commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") in our testbed as well. We continue to observe the same crash after integrating the commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") On reviewing the change, the port lock should be taken prior to checking for if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer uart_state->xmit. Traceback: [11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference at virtual address 0000003b [11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180 [11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120 [11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>] lr : [<ffffffc0003747cc>] pstate: 000001c5 [11/27/2018 06:24:32.4950] sp : ffffffc076433d30 [11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140 [11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580 [11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140 [11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000 [11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076 [11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000 [11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68 [11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948 [11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333 [11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131 [11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070 [11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b [11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008 [11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e [11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b [11/27/2018 06:24:32.4950] CPU2: stopping [11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3 [11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT) [11/27/2018 06:24:32.4950] Call trace: [11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150 [11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20 [11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0 [11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0 [11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90 Fixes: a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Samir Virmani <samir@embedur.com> Acked-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'tty-5.0-rc2' of ↵Linus Torvalds2019-01-132-24/+32
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are 2 tty and serial fixes for 5.0-rc2 that resolve some reported issues. The first is a simple serial driver fix for a regression that showed up in 5.0-rc1. The second one resolves a number of reported issues with the recent tty locking fixes that went into 5.0-rc1. Lots of people have tested the second one and say it resolves their issues. Both have been in linux-next with no reported issues" * tag 'tty-5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: Don't hold ldisc lock in tty_reopen() if ldisc present serial: lantiq: Do not swap register read/writes
| * tty: Don't hold ldisc lock in tty_reopen() if ldisc presentDmitry Safonov2019-01-111-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try to get reference for ldisc during tty_reopen(). If ldisc present, we don't need to do tty_ldisc_reinit() and lock the write side for line discipline semaphore. Effectively, it optimizes fast-path for tty_reopen(), but more importantly it won't interrupt ongoing IO on the tty as no ldisc change is needed. Fixes user-visible issue when tty_reopen() interrupted login process for user with a long password, observed and reported by Lukas. Fixes: c96cf923a98d ("tty: Don't block on IO when ldisc change is pending") Fixes: 83d817f41070 ("tty: Hold tty_ldisc_lock() during tty_reopen()") Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Lukas F. Hartmann <lukas@mntmn.com> Tested-by: Lukas F. Hartmann <lukas@mntmn.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: lantiq: Do not swap register read/writesHauke Mehrtens2019-01-081-17/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ltq_r32() and ltq_w32() macros use the __raw_readl() and __raw_writel() functions which do not swap the value to little endian. On the big endian vrx200 SoC the UART is operated in big endian IO mode, the readl() and write() functions convert the value to little endian first and then the driver does not work any more on this SoC. Currently the vrx200 SoC selects the CONFIG_SWAP_IO_SPACE option, without this option the serial driver would work, but PCI devices do not work any more. This patch makes the driver use the __raw_readl() and __raw_writel() functions which do not swap the endianness. On big endian system it is assumed that the device should be access in big endian IO mode and on a little endian system it would be access in little endian mode. Fixes: 89b8bd2082bb ("serial: lantiq: Use readl/writel instead of ltq_r32/ltq_w32") Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Acked-by: John Crispin <john@phrozen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty/serial: Add RISC-V SBI earlycon supportAnup Patel2019-01-093-0/+41
|/ | | | | | | | | | | | In RISC-V, the M-mode runtime firmware provide SBI calls for debug prints. This patch adds earlycon support using RISC-V SBI console calls. To enable it, just pass "earlycon=sbi" in kernel parameters. Signed-off-by: Anup Patel <anup@brainfault.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
* Merge tag 'armsoc-late' of ↵Linus Torvalds2019-01-053-0/+851
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull more ARM SoC updates from Olof Johansson: "A few updates that we merged late but are low risk for regressions for other platforms (and a few other straggling patches): - I mis-tagged the 'drivers' branch, and missed 3 patches. Merged in here. They're for a driver for the PL353 SRAM controller and a build fix for the qualcomm scm driver. - A new platform, RDA Micro RDA8810PL (Cortex-A5 w/ integrated Vivante GPU, 256MB RAM, Wifi). This includes some acked platform-specific drivers (serial, etc). This also include DTs for two boards with this SoC, OrangePi 2G and OrangePi i86. - i.MX8 is another new platform (NXP, 4x Cortex-A53 + Cortex-M4, 4K video playback offload). This is the first i.MX 64-bit SoC. - Some minor updates to Samsung boards (adding a few peripherals in DTs). - Small rework for SMP bootup on STi platforms. - A couple of TEE driver fixes. - A couple of new config options (bcm2835 thermal, Uniphier MDMAC) enabled in defconfigs" * tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (27 commits) ARM: multi_v7_defconfig: enable CONFIG_UNIPHIER_MDMAC arm64: defconfig: Re-enable bcm2835-thermal driver MAINTAINERS: Add entry for RDA Micro SoC architecture tty: serial: Add RDA8810PL UART driver ARM: dts: rda8810pl: Add interrupt support for UART dt-bindings: serial: Document RDA Micro UART ARM: dts: rda8810pl: Add timer support ARM: dts: Add devicetree for OrangePi i96 board ARM: dts: Add devicetree for OrangePi 2G IoT board ARM: dts: Add devicetree for RDA8810PL SoC ARM: Prepare RDA8810PL SoC dt-bindings: arm: Document RDA8810PL and reference boards dt-bindings: Add RDA Micro vendor prefix ARM: sti: remove pen_release and boot_lock arm64: dts: exynos: Add Bluetooth chip to TM2(e) boards arm64: dts: imx8mq-evk: enable watchdog arm64: dts: imx8mq: add watchdog devices MAINTAINERS: add i.MX8 DT path to i.MX architecture arm64: add support for i.MX8M EVK board arm64: add basic DTS for i.MX8MQ ...
| * tty: serial: Add RDA8810PL UART driverManivannan Sadhasivam2018-12-313-0/+851
| | | | | | | | | | | | | | | | | | | | Add UART driver for RDA Micro RDA8810PL SoC. Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Olof Johansson <olof@lixom.net>
* | Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'tty-4.21-rc1' of ↵Linus Torvalds2018-12-2936-301/+803
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the large TTY/Serial driver set of patches for 4.21-rc1. A number of small serial driver changes along with some good tty core fixes for long-reported issues with locking. There is also a new console font added to the tree, for high-res screens, so that should be helpful for many. The last patch in the series is a revert of an older one in the tree, it came late but it resolves a reported issue that linux-next was having for some people. Full details are in the shortlog, and all of these, with the exception of the revert, have been in linux-next for a while with no reported issues" * tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits) Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250" serial: sccnxp: Allow to use non-standard baud rates serial: sccnxp: Adds a delay between sequential read/write cycles tty: serial: qcom_geni_serial: Fix UART hang tty: serial: qcom_geni_serial: Fix wrap around of TX buffer serial: max310x: Fix tx_empty() callback dt-bindings: serial: sh-sci: Document r8a774c0 bindings dt-bindings: serial: sh-sci: Document r8a774a1 bindings Fonts: New Terminus large console font dt-bindings: serial: lpuart: add imx8qxp compatible string serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly serial: uartps: Fix error path when alloc failed serial: uartps: Check if the device is a console serial: uartps: Add the device_init_wakeup tty: serial: samsung: Increase maximum baudrate tty: serial: samsung: Properly set flags in autoCTS mode tty: Use of_node_name_{eq,prefix} for node name comparisons tty/serial: do not free trasnmit buffer page under port lock serial: 8250: Rate limit serial port rx interrupts during input overruns dt-bindings: serial: 8250: Add rate limit for serial port input overruns ...
| * | Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250"Greg Kroah-Hartman2018-12-241-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 6d11023c345e369bcb9d5a68b271764e362c1f6e. It causes issues with Guenter's test systems and since there seems to not be any agreement about _why_ this is a problem, but reverting it fixes things, let's revert until the root cause is found. Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: sccnxp: Allow to use non-standard baud ratesAlexander Shiyan2018-12-201-3/+19
| | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for the use of non-standard baud rates. For these purposes, we use the built-in timer/counter. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: sccnxp: Adds a delay between sequential read/write cyclesAlexander Shiyan2018-12-201-5/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a delay between sequential read/write cycles, to ensure the required minimum inactive time (tRWD). A time value from the datasheet has been added for each type of supported chips. The “inline” compiler attribute has been removed from the read/write functions, simply allow the compiler to control this. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: qcom_geni_serial: Fix UART hangRyan Case2018-12-201-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a serial console write occured while a UART transmit command was waiting for a done signal then no further data would be sent until something new kicked the system into gear. If there is already data waiting in the circular buffer we must re-enable the tx watermark so we receive the expected interrupts. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Evan Green <evgreen@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: qcom_geni_serial: Fix wrap around of TX bufferMatthias Kaehlcke2018-12-201-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before commit a1fee899e5bed ("tty: serial: qcom_geni_serial: Fix softlock") the size of TX transfers was limited to the TX FIFO size, and wrap arounds of the UART circular buffer were split into two transfers. With the commit wrap around are allowed within a transfer. The TX FIFO of the geni serial port uses a word size of 4 bytes. In case of a circular buffer wrap within a transfer the driver currently may write an incomplete word to the FIFO, with some bytes containing data from the circular buffer and others being zero. Since the transfer isn't completed yet the zero bytes are sent as if they were actual data. Handle wrap arounds of the TX buffer properly and ensure that words written to the TX FIFO always contain valid data (unless the transfer is completed). Fixes: a1fee899e5bed ("tty: serial: qcom_geni_serial: Fix softlock") Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Evan Green <evgreen@chromium.org> Tested-by: Ryan Case <ryandcase@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: max310x: Fix tx_empty() callbackAlexander Shiyan2018-12-191-5/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function max310x_tx_empty() accesses the IRQSTS register, which is cleared by IC when reading, so if there is an interrupt status, we will lose it. This patch implement the transmitter check only by the current FIFO level. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: uartps: Fix interrupt mask issue to handle the RX interrupts properlyNava kishore Manne2018-12-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch Correct the RX interrupt mask value to handle the RX interrupts properly. Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: uartps: Fix error path when alloc failedMichal Simek2018-12-191-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | When cdns_uart_console allocation failed there is a need to also clear ID from ID list. Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: uartps: Check if the device is a consoleShubhrajyoti Datta2018-12-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | While checking for console_suspend_enabled also check if the device is a console. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: uartps: Add the device_init_wakeupShubhrajyoti Datta2018-12-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Initialise the device wakeup. The device_init_wakeup is needed for the wakeup to work by default. Uart can be configured as the primary wakeup source so it is good to enable wakeup by default. The same functionality is enabled also by 8250_omap, atmel_serial, omap-serial and stm32-usart. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: samsung: Increase maximum baudrateSeung-Woo Kim2018-12-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This driver can be used to communicate with Bluetooth chip in high-speed UART mode, so increase the maximum baudrate to 3Mbps. Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com> [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: samsung: Properly set flags in autoCTS modeBeomho Seo2018-12-171-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support") has changed the way the autoCTS mode is handled. According to that change, serial drivers which enable H/W autoCTS mode must set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling TX. This patch adds proper handling of UPSTAT_AUTOCTS flag. Signed-off-by: Beomho Seo <beomho.seo@samsung.com> [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: Use of_node_name_{eq,prefix} for node name comparisonsRob Herring2018-12-175-19/+10Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert string compares of DT node names to use of_node_name_eq helper instead. This removes direct access to the node name pointer. For hvc, the code can also be simplified by using of_stdout pointer instead of searching again for the stdout node. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-serial@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty/serial: do not free trasnmit buffer page under port lockSergey Senozhatsky2018-12-171-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LKP has hit yet another circular locking dependency between uart console drivers and debugobjects [1]: CPU0 CPU1 rhltable_init() __init_work() debug_object_init uart_shutdown() /* db->lock */ /* uart_port->lock */ debug_print_object() free_page() printk() call_console_drivers() debug_check_no_obj_freed() /* uart_port->lock */ /* db->lock */ debug_print_object() So there are two dependency chains: uart_port->lock -> db->lock And db->lock -> uart_port->lock This particular circular locking dependency can be addressed in several ways: a) One way would be to move debug_print_object() out of db->lock scope and, thus, break the db->lock -> uart_port->lock chain. b) Another one would be to free() transmit buffer page out of db->lock in UART code; which is what this patch does. It makes sense to apply a) and b) independently: there are too many things going on behind free(), none of which depend on uart_port->lock. The patch fixes transmit buffer page free() in uart_shutdown() and, additionally, in uart_port_startup() (as was suggested by Dmitry Safonov). [1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Waiman Long <longman@redhat.com> Cc: Dmitry Safonov <dima@arista.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: 8250: Rate limit serial port rx interrupts during input overrunsDarwin Dingel2018-12-173-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a serial port gets faulty or gets flooded with inputs, its interrupt handler starts to work double time to get the characters to the workqueue for the tty layer to handle them. When this busy time on the serial/tty subsystem happens during boot, where it is also busy on the userspace trying to initialise, some processes can continuously get preempted and will be on hold until the interrupts subside. The fix is to backoff on processing received characters for a specified amount of time when an input overrun is seen (received a new character before the previous one is processed). This only stops receive and will continue to transmit characters to serial port. After the backoff period is done, it receive will be re-enabled. This is optional and will only be enabled by setting 'overrun-throttle-ms' in the dts. Signed-off-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: qcom_geni_serial: Remove interrupt stormRyan Case2018-12-171-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given transaction so we don't continue to receive a flurry of free space interrupts while waiting for the M_CMD_DONE notification. Re-enable the watermark when establishing the next transaction. Also clear the watermark interrupt after filling the FIFO so we do not receive notification again prior to actually having free space. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failureGeert Uytterhoeven2018-12-171-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler. Hence if DMA submission fails, the interrupt handler should resume handling reception using PIO, else no more data is received. Make sci_submit_rx() return an error indicator, so the receive interrupt handler can act appropriately. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallbackGeert Uytterhoeven2018-12-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When falling back to PIO, active_rx must be set to a different value than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a match, leading to a NULL pointer dereference in rx_timer_fn() later. Use zero instead, which is the same value as after driver initialization. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: sh-sci: Fix locking in sci_submit_rx()Geert Uytterhoeven2018-12-171-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some callers of sci_submit_rx() hold the port spinlock, others don't. During fallback to PIO, the driver needs to obtain the port spinlock. If the lock was already held, spinlock recursion is detected, causing a deadlock: BUG: spinlock recursion on CPU#0. Fix this by adding a flag parameter to sci_submit_rx() for the caller to indicate the port spinlock is already held, so spinlock recursion can be avoided. Move the spin_lock_irqsave() up, so all DMA disable steps are protected, which is safe as the recently introduced dmaengine_terminate_async() can be called in atomic context. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | Merge 4.20-rc6 into tty-nextGreg Kroah-Hartman2018-12-104-14/+20
| |\ \ | | | | | | | | | | | | | | | | | | | | We want the TTY changes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | Revert "tty: xilinx_uartps: Correct return value in probe"Greg Kroah-Hartman2018-12-061-12/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit eca42d4cf3c591c36312c52707e0a712e0c7256a. During review it was rejected, so drop it from the tree. Cc: Rajan Vaja <RAJANV@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty/ldsem: Decrement wait_readers on timeouted down_read()Dmitry Safonov2018-12-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems like when ldsem_down_read() fails with timeout, it misses update for sem->wait_readers. By that reason, when writer finally releases write end of the semaphore __ldsem_wake_readers() does adjust sem->count with wrong value: sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS) I.e, if update comes with 1 missed wait_readers decrement, sem->count will be 0x100000001 which means that there is active reader and it'll make any further writer to fail in acquiring the semaphore. It looks like, this is a dead-code, because ldsem_down_read() is never called with timeout different than MAX_SCHEDULE_TIMEOUT, so it might be worth to delete timeout parameter and error path fall-back.. Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty/ldsem: Add lockdep asserts for ldisc_semDmitry Safonov2018-12-051-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure under CONFIG_LOCKDEP that each change to line discipline is done with held write semaphor. Otherwise potential reader will have a good time dereferencing incomplete/uninitialized ldisc. An exception here is tty_ldisc_open(), as it's called without ldisc_sem locked by tty_init_dev() => tty_ldisc_setup() for the tty->link. It seem valid as tty_init_dev() will call tty_driver_install_tty() which will find ops->install(). Install will establish tty->link in pty_common_install(), just after allocation of slave tty with alloc_tty_struct(). So, no one should have a reference to slave pty yet. Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty/ldsem: Convert to regular lockdep annotationsPeter Zijlstra2018-12-051-37/+14Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For some reason ldsem has its own lockdep wrappers, make them go away. Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty: Simplify tty->count math in tty_reopen()Dmitry Safonov2018-12-051-8/+5Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter. Simplify math by increasing the counter after reinit success. Cc: Jiri Slaby <jslaby@suse.com> Link: lkml.kernel.org/r/<20180829022353.23568-2-dima@arista.com> Suggested-by: Jiri Slaby <jslaby@suse.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty: Don't block on IO when ldisc change is pendingDmitry Safonov2018-12-054-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There might be situations where tty_ldisc_lock() has blocked, but there is already IO on tty and it prevents line discipline changes. It might theoretically turn into dead-lock. Basically, provide more priority to pending tty_ldisc_lock() than to servicing reads/writes over tty. User-visible issue was reported by Mikulas where on pa-risc with Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper locking in tty_reopen(). Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty: Hold tty_ldisc_lock() during tty_reopen()Dmitry Safonov2018-12-051-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty_ldisc_reinit() doesn't race with neither tty_ldisc_hangup() nor set_ldisc() nor tty_ldisc_release() as they use tty lock. But it races with anyone who expects line discipline to be the same after hoding read semaphore in tty_ldisc_ref(). We've seen the following crash on v4.9.108 stable: BUG: unable to handle kernel paging request at 0000000000002260 IP: [..] n_tty_receive_buf_common+0x5f/0x86d Workqueue: events_unbound flush_to_ldisc Call Trace: [..] n_tty_receive_buf2 [..] tty_ldisc_receive_buf [..] flush_to_ldisc [..] process_one_work [..] worker_thread [..] kthread [..] ret_from_fork tty_ldisc_reinit() should be called with ldisc_sem hold for writing, which will protect any reader against line discipline changes. Cc: Jiri Slaby <jslaby@suse.com> Cc: stable@vger.kernel.org # b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf") Reviewed-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+3aa9784721dfb90e984d@syzkaller.appspotmail.com Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Dmitry Safonov <dima@arista.com> Tested-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty/ldsem: Wake up readers after timed out down_write()Dmitry Safonov2018-12-051-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ldsem_down_read() will sleep if there is pending writer in the queue. If the writer times out, readers in the queue should be woken up, otherwise they may miss a chance to acquire the semaphore until the last active reader will do ldsem_up_read(). There was a couple of reports where there was one active reader and other readers soft locked up: Showing all locks held in the system: 2 locks held by khungtaskd/17: #0: (rcu_read_lock){......}, at: watchdog+0x124/0x6d1 #1: (tasklist_lock){.+.+..}, at: debug_show_all_locks+0x72/0x2d3 2 locks held by askfirst/123: #0: (&tty->ldisc_sem){.+.+.+}, at: ldsem_down_read+0x46/0x58 #1: (&ldata->atomic_read_lock){+.+...}, at: n_tty_read+0x115/0xbe4 Prevent readers wait for active readers to release ldisc semaphore. Link: lkml.kernel.org/r/20171121132855.ajdv4k6swzhvktl6@wfg-t540p.sh.intel.com Link: lkml.kernel.org/r/20180907045041.GF1110@shao2-debian Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty/sysrq: Do not call sync directly from sysrq_do_reset()Mark Tomlinson2018-12-051-2/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysrq_do_reset() is called in softirq context, so it cannot call sync() directly. Instead, call orderly_reboot(), which creates a work item to run /sbin/reboot, or do emergency_sync and restart if the command fails. Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: 8250-mtk: add uart DMA supportLong Cheng2018-12-051-1/+209
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify uart register to support DMA function. Signed-off-by: Long Cheng <long.cheng@mediatek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty: xilinx_uartps: Correct return value in probeRajan Vaja2018-12-051-14/+12Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Existing driver checks for alternate clock if devm_clk_get() fails and returns error code for last clock failure. If xilinx_uartps is called before clock driver, devm_clk_get() returns -EPROBE_DEFER. In this case, probe should not check for alternate clock as main clock is already present in DTS and return -EPROBE_DEFER only. This patch fixes it by not checking for alternate clock when main clock get returns -EPROBE_DEFER. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>