[PATCH] Fix for AMBA PL011 serial driver (tx_empty logic)

[PATCH] Fix for AMBA PL011 serial driver (tx_empty logic)

[Simon Budig]

From: Simon Budig <simon@budig.de>

Hi all.

This is a resend of a patch i submitted a few days ago although with a
mangled formatting. I don't know who maintains the PL011 AMBA driver, so
I hope someone steps up and helps me in bringing this upstream.

There is a problem with the logic of tx_empty in the amba-pl011 serial
port driver. Instead of checking for an empty FIFO it checks for a
not-full FIFO, which - according to Documentation/serial/driver - is
wrong.

Thanks,
        Simon

Simon Budig (1):
  Fix logic of tx_empty.

 drivers/tty/serial/amba-pl011.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

[PATCH] Fix logic of tx_empty.

[Simon Budig]

From: Simon Budig <simon@budig.de>

   test for TX-FIFO *not empty* instead of TX-FIFO full.

Signed-off-by: Simon Budig <simon.budig@kernelconcepts.de>
---
 drivers/tty/serial/amba-pl011.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 05eb292..a23b419 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -792,7 +792,7 @@ static unsigned int pl01x_tx_empty(struct uart_port *port)
 {
 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
 	unsigned int status = readw(uap->port.membase + UART01x_FR);
-	return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
+	return (status & UART01x_FR_BUSY) || !(status & UART011_FR_TXFE) ? 0 : TIOCSER_TEMT;
 }
 
 static unsigned int pl01x_get_mctrl(struct uart_port *port)
-- 
1.7.0.4

[PATCH] Fix logic of tx_empty.

[Simon Budig]

   test for TX-FIFO *not empty* instead of TX-FIFO full.

Signed-off-by: Simon Budig <simon.budig@kernelconcepts.de>
---
 drivers/tty/serial/amba-pl011.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 05eb292..a23b419 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -792,7 +792,7 @@ static unsigned int pl01x_tx_empty(struct uart_port *port)
 {
 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
 	unsigned int status = readw(uap->port.membase + UART01x_FR);
-	return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
+	return (status & UART01x_FR_BUSY) || !(status & UART011_FR_TXFE) ? 0 : TIOCSER_TEMT;
 }
 
 static unsigned int pl01x_get_mctrl(struct uart_port *port)
-- 
1.7.0.4



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