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path: root/drivers/tty/serial/sh-sci.c
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Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
-rw-r--r--drivers/tty/serial/sh-sci.c45
1 files changed, 30 insertions, 15 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 71707e8e6e3f..da5ddfc14778 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1450,8 +1450,7 @@ static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
chan = dma_request_slave_channel(port->dev,
dir == DMA_MEM_TO_DEV ? "tx" : "rx");
if (!chan) {
- dev_warn(port->dev,
- "dma_request_slave_channel_compat failed\n");
+ dev_warn(port->dev, "dma_request_slave_channel failed\n");
return NULL;
}
@@ -1558,7 +1557,16 @@ static void sci_free_dma(struct uart_port *port)
if (s->chan_rx)
sci_rx_dma_release(s, false);
}
-#else
+
+static void sci_flush_buffer(struct uart_port *port)
+{
+ /*
+ * In uart_flush_buffer(), the xmit circular buffer has just been
+ * cleared, so we have to reset tx_dma_len accordingly.
+ */
+ to_sci_port(port)->tx_dma_len = 0;
+}
+#else /* !CONFIG_SERIAL_SH_SCI_DMA */
static inline void sci_request_dma(struct uart_port *port)
{
}
@@ -1566,7 +1574,9 @@ static inline void sci_request_dma(struct uart_port *port)
static inline void sci_free_dma(struct uart_port *port)
{
}
-#endif
+
+#define sci_flush_buffer NULL
+#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
{
@@ -2581,6 +2591,7 @@ static const struct uart_ops sci_uart_ops = {
.break_ctl = sci_break_ctl,
.startup = sci_startup,
.shutdown = sci_shutdown,
+ .flush_buffer = sci_flush_buffer,
.set_termios = sci_set_termios,
.pm = sci_pm,
.type = sci_type,
@@ -2950,6 +2961,7 @@ static inline int sci_probe_earlyprintk(struct platform_device *pdev)
static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
+static DEFINE_MUTEX(sci_uart_registration_lock);
static struct uart_driver sci_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "sci",
@@ -3078,6 +3090,16 @@ static int sci_probe_single(struct platform_device *dev,
return -EINVAL;
}
+ mutex_lock(&sci_uart_registration_lock);
+ if (!sci_uart_driver.state) {
+ ret = uart_register_driver(&sci_uart_driver);
+ if (ret) {
+ mutex_unlock(&sci_uart_registration_lock);
+ return ret;
+ }
+ }
+ mutex_unlock(&sci_uart_registration_lock);
+
ret = sci_init_single(dev, sciport, index, p, false);
if (ret)
return ret;
@@ -3201,24 +3223,17 @@ static struct platform_driver sci_driver = {
static int __init sci_init(void)
{
- int ret;
-
pr_info("%s\n", banner);
- ret = uart_register_driver(&sci_uart_driver);
- if (likely(ret == 0)) {
- ret = platform_driver_register(&sci_driver);
- if (unlikely(ret))
- uart_unregister_driver(&sci_uart_driver);
- }
-
- return ret;
+ return platform_driver_register(&sci_driver);
}
static void __exit sci_exit(void)
{
platform_driver_unregister(&sci_driver);
- uart_unregister_driver(&sci_uart_driver);
+
+ if (sci_uart_driver.state)
+ uart_unregister_driver(&sci_uart_driver);
}
#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE