* Re: [PATCH RESEND] tty/serial/imx: Enable TXEN bit in imx_poll_init().
2020-12-01 23:03 [PATCH RESEND] tty/serial/imx: Enable TXEN bit in imx_poll_init() jiladahe1997
@ 2020-12-01 16:47 ` Greg KH
2020-12-02 3:16 ` jiladahe1997
0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2020-12-01 16:47 UTC (permalink / raw)
To: jiladahe1997; +Cc: shawnguo, s.hauer, linux-imx, linux-kernel, 972931182
On Wed, Dec 02, 2020 at 07:03:08AM +0800, jiladahe1997 wrote:
> From: Mingrui Ren <jiladahe1997@gmail.com>
>
> As described in Documentation, poll_init() is called by kgdb to initialize
> hardware which supports both poll_put_char() and poll_get_char().
>
> It's necessary to enable TXEN bit, otherwise, it will cause hardware fault
> and kernel panic when calling imx_poll_put_char().
>
> Generally, if use /dev/ttymxc0 as kgdb console as well as system
> console, ttymxc0 is initialized early by system console which does enable
> TXEN bit.But when use /dev/ttymxc1 as kgbd console, ttymxc1 is only
> initialized by imx_poll_init() cannot enable the TXEN bit, which will
> cause kernel panic.
>
> Signed-off-by: Mingrui Ren <jiladahe1997@gmail.com>
> ---
> Hi, thanks for your reply, and sorry for sending two identical emails.
> The email service I used before seems to have some problems,
> so I switched to gmail.This is the "correct" version, please check.
>
> drivers/tty/serial/imx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 43c6d7142fdd..7c665db3d897 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -1829,7 +1829,7 @@ static int imx_uart_poll_init(struct uart_port *port)
> ucr1 |= UCR1_UARTEN;
> ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
>
> - ucr2 |= UCR2_RXEN;
> + ucr2 |= UCR2_RXEN|UCR2_TXEN;
Didn't checkpatch complain about this? Please use ' ' characters around
the '|' character.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH RESEND] tty/serial/imx: Enable TXEN bit in imx_poll_init().
@ 2020-12-01 23:03 jiladahe1997
2020-12-01 16:47 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: jiladahe1997 @ 2020-12-01 23:03 UTC (permalink / raw)
To: gregkh, shawnguo, s.hauer; +Cc: linux-imx, linux-kernel, 972931182, Mingrui Ren
From: Mingrui Ren <jiladahe1997@gmail.com>
As described in Documentation, poll_init() is called by kgdb to initialize
hardware which supports both poll_put_char() and poll_get_char().
It's necessary to enable TXEN bit, otherwise, it will cause hardware fault
and kernel panic when calling imx_poll_put_char().
Generally, if use /dev/ttymxc0 as kgdb console as well as system
console, ttymxc0 is initialized early by system console which does enable
TXEN bit.But when use /dev/ttymxc1 as kgbd console, ttymxc1 is only
initialized by imx_poll_init() cannot enable the TXEN bit, which will
cause kernel panic.
Signed-off-by: Mingrui Ren <jiladahe1997@gmail.com>
---
Hi, thanks for your reply, and sorry for sending two identical emails.
The email service I used before seems to have some problems,
so I switched to gmail.This is the "correct" version, please check.
drivers/tty/serial/imx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 43c6d7142fdd..7c665db3d897 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1829,7 +1829,7 @@ static int imx_uart_poll_init(struct uart_port *port)
ucr1 |= UCR1_UARTEN;
ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
- ucr2 |= UCR2_RXEN;
+ ucr2 |= UCR2_RXEN|UCR2_TXEN;
ucr2 &= ~UCR2_ATEN;
imx_uart_writel(sport, ucr1, UCR1);
--
2.29.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH RESEND] tty/serial/imx: Enable TXEN bit in imx_poll_init().
2020-12-01 16:47 ` Greg KH
@ 2020-12-02 3:16 ` jiladahe1997
0 siblings, 0 replies; 3+ messages in thread
From: jiladahe1997 @ 2020-12-02 3:16 UTC (permalink / raw)
To: Greg KH; +Cc: shawnguo, s.hauer, linux-imx, linux-kernel, 972931182
On 2020/12/2 0:47, Greg KH wrote:
> On Wed, Dec 02, 2020 at 07:03:08AM +0800, jiladahe1997 wrote:
>> From: Mingrui Ren <jiladahe1997@gmail.com>
>>
>> As described in Documentation, poll_init() is called by kgdb to initialize
>> hardware which supports both poll_put_char() and poll_get_char().
>>
>> It's necessary to enable TXEN bit, otherwise, it will cause hardware fault
>> and kernel panic when calling imx_poll_put_char().
>>
>> Generally, if use /dev/ttymxc0 as kgdb console as well as system
>> console, ttymxc0 is initialized early by system console which does enable
>> TXEN bit.But when use /dev/ttymxc1 as kgbd console, ttymxc1 is only
>> initialized by imx_poll_init() cannot enable the TXEN bit, which will
>> cause kernel panic.
>>
>> Signed-off-by: Mingrui Ren <jiladahe1997@gmail.com>
>> ---
>> Hi, thanks for your reply, and sorry for sending two identical emails.
>> The email service I used before seems to have some problems,
>> so I switched to gmail.This is the "correct" version, please check.
>>
>> drivers/tty/serial/imx.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
>> index 43c6d7142fdd..7c665db3d897 100644
>> --- a/drivers/tty/serial/imx.c
>> +++ b/drivers/tty/serial/imx.c
>> @@ -1829,7 +1829,7 @@ static int imx_uart_poll_init(struct uart_port *port)
>> ucr1 |= UCR1_UARTEN;
>> ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
>>
>> - ucr2 |= UCR2_RXEN;
>> + ucr2 |= UCR2_RXEN|UCR2_TXEN;
> Didn't checkpatch complain about this? Please use ' ' characters around
> the '|' character.
>
> thanks,
>
> greg k-h
Yeah, checkpatch didn't complain:
root@iZ2zefbvkcoj7o7ledf4oqZ:~/workspace/linux-imx$
./scripts/checkpatch.pl
0001-tty-serial-imx-Enable-TXEN-bit-in-imx_poll_init.patch
total: 0 errors, 0 warnings, 8 lines checked
0001-tty-serial-imx-Enable-TXEN-bit-in-imx_poll_init.patch has no
obvious style problems and is ready for submission.
Maybe some patches should be submitted to checkpatch.pl :).
Anyway, I will add ' ' characters and send PATCH V2.
Thanks,
Mingrui Ren
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-12-02 3:17 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-12-01 23:03 [PATCH RESEND] tty/serial/imx: Enable TXEN bit in imx_poll_init() jiladahe1997
2020-12-01 16:47 ` Greg KH
2020-12-02 3:16 ` jiladahe1997
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