diff mbox

[v2] serial: omap: fix the reciever line error case

Message ID 1348238239-18510-1-git-send-email-shubhrajyoti@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Shubhrajyoti Datta Sept. 21, 2012, 2:37 p.m. UTC
This patch does the following
- In case of errors if there least one data character in the RX FIFO
read it otherwise it may stall the receiver.

This is recommended in the interrupt reset method in the table 23-246 of
the omap4 TRM.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
- Tested on omap4sdp.
- pm tested hitting off in idle and suspend.
- v2 changes update the changelogs.
- Also remove the dummy check as FE , PE , BI and OE are the only
receiver errors.

 drivers/tty/serial/omap-serial.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

Comments

Felipe Balbi Sept. 21, 2012, 4:01 p.m. UTC | #1
On Fri, Sep 21, 2012 at 08:07:19PM +0530, Shubhrajyoti D wrote:
> This patch does the following
> - In case of errors if there least one data character in the RX FIFO
> read it otherwise it may stall the receiver.
> 
> This is recommended in the interrupt reset method in the table 23-246 of
> the omap4 TRM.
> 
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>

FWIW:

Reviewed-by: Felipe Balbi <balbi@ti.com>

> ---
> - Tested on omap4sdp.
> - pm tested hitting off in idle and suspend.
> - v2 changes update the changelogs.
> - Also remove the dummy check as FE , PE , BI and OE are the only
> receiver errors.
> 
>  drivers/tty/serial/omap-serial.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index a0d4460..4fea16b 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -334,6 +334,10 @@ static unsigned int check_modem_status(struct uart_omap_port *up)
>  static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
>  {
>  	unsigned int flag;
> +	unsigned char ch = 0;
> +
> +	if (likely(lsr & UART_LSR_DR))
> +		ch = serial_in(up, UART_RX);
>  
>  	up->port.icount.rx++;
>  	flag = TTY_NORMAL;
> -- 
> 1.7.5.4
> 
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Kevin Hilman Sept. 21, 2012, 9:46 p.m. UTC | #2
Shubhrajyoti D <shubhrajyoti@ti.com> writes:

> This patch does the following
> - In case of errors if there least one data character in the RX FIFO
> read it otherwise it may stall the receiver.
>
> This is recommended in the interrupt reset method in the table 23-246 of
> the omap4 TRM.
>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
> ---
> - Tested on omap4sdp.
> - pm tested hitting off in idle and suspend.
> - v2 changes update the changelogs.
> - Also remove the dummy check as FE , PE , BI and OE are the only
> receiver errors.

Tested-by: Kevin Hilman <khilman@ti.com>

This one also makes the regression I was seeing on 3530/Overo disappear.

Thanks,

Kevin
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diff mbox

Patch

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index a0d4460..4fea16b 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -334,6 +334,10 @@  static unsigned int check_modem_status(struct uart_omap_port *up)
 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
 {
 	unsigned int flag;
+	unsigned char ch = 0;
+
+	if (likely(lsr & UART_LSR_DR))
+		ch = serial_in(up, UART_RX);
 
 	up->port.icount.rx++;
 	flag = TTY_NORMAL;