Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20170109' into staging

target-arm queue:
 * i2c: Allow I2C devices to NAK start events
 * hw/char: QOM'ify exynos4210_uart.c
 * clean up and refactor virt-acpi-build.c
 * virt-acpi-build: Don't incorrectly claim architectural timer
   to be edge-triggered
 * m25p80: Don't let rogue SPI controllers cause buffer overruns
 * imx_spi: Remove broken MSGDATA register support

# gpg: Signature made Mon 09 Jan 2017 11:52:49 GMT
# gpg:                using RSA key 0x3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20170109: (21 commits)
  hw/ssi/imx_spi.c: Remove MSGDATA register support
  m25p80: don't let rogue SPI controllers cause buffer overruns
  hw/arm/virt-acpi-build: Don't incorrectly claim architectural timer to be edge-triggered
  hw/arm/virt: remove VirtGuestInfo
  hw/arm/virt-acpi-build: don't save VirtGuestInfo on AcpiBuildState
  hw/arm/virt-acpi-build: remove redundant members from VirtGuestInfo
  hw/arm/virt: pass VirtMachineState instead of VirtGuestInfo
  hw/arm/virt: move VirtMachineState/Class to virt.h
  hw/arm/virt: remove include/hw/arm/virt-acpi-build.h
  hw/arm/virt: eliminate struct VirtGuestInfoState
  hw/arm/virt: use VirtMachineState.gic_version
  hw/arm/virt: parameter passing cleanups
  hw/arm/virt-acpi-build: fadt: improve flag naming
  hw/arm/virt-acpi-build: gtdt: improve flag naming
  hw/arm/virt-acpi-build: name GIC CPU Interface Structure appropriately
  hw/arm/virt-acpi-build: add all missing cpu_to_le's
  hw/arm/virt: Don't incorrectly claim architectural timer to be edge-triggered
  hw/arm/virt: Rename 'vbi' variables to 'vms'
  hw/arm/virt: Merge VirtBoardInfo and VirtMachineState
  hw/char: QOM'ify exynos4210_uart.c
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 25 insertions, 6 deletions

diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index e40781ea3b..2c1234cdff 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -88,18 +88,26 @@ int i2c_bus_busy(I2CBus *bus)
     return !QLIST_EMPTY(&bus->current_devs);
 }
 
+/* TODO: Make this handle multiple masters.  */
 /*
- * Returns non-zero if the address is not valid.  If this is called
- * again without an intervening i2c_end_transfer(), like in the SMBus
- * case where the operation is switched from write to read, this
- * function will not rescan the bus and thus cannot fail.
+ * Start or continue an i2c transaction.  When this is called for the
+ * first time or after an i2c_end_transfer(), if it returns an error
+ * the bus transaction is terminated (or really never started).  If
+ * this is called after another i2c_start_transfer() without an
+ * intervening i2c_end_transfer(), and it returns an error, the
+ * transaction will not be terminated.  The caller must do it.
+ *
+ * This corresponds with the way real hardware works.  The SMBus
+ * protocol uses a start transfer to switch from write to read mode
+ * without releasing the bus.  If that fails, the bus is still
+ * in a transaction.
  */
-/* TODO: Make this handle multiple masters.  */
 int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
 {
     BusChild *kid;
     I2CSlaveClass *sc;
     I2CNode *node;
+    bool bus_scanned = false;
 
     if (address == I2C_BROADCAST) {
         /*
@@ -130,6 +138,7 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
                 }
             }
         }
+        bus_scanned = true;
     }
 
     if (QLIST_EMPTY(&bus->current_devs)) {
@@ -137,11 +146,21 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
     }
 
     QLIST_FOREACH(node, &bus->current_devs, next) {
+        int rv;
+
         sc = I2C_SLAVE_GET_CLASS(node->elt);
         /* If the bus is already busy, assume this is a repeated
            start condition.  */
+
         if (sc->event) {
-            sc->event(node->elt, recv ? I2C_START_RECV : I2C_START_SEND);
+            rv = sc->event(node->elt, recv ? I2C_START_RECV : I2C_START_SEND);
+            if (rv && !bus->broadcast) {
+                if (bus_scanned) {
+                    /* First call, terminate the transfer. */
+                    i2c_end_transfer(bus);
+                }
+                return rv;
+            }
         }
     }
     return 0;