* Re: [PATCH] tty: serial: samsung_tty: loopback mode support
2022-06-27 3:23 ` [PATCH] tty: serial: samsung_tty: loopback mode support Chanho Park
@ 2022-06-27 11:28 ` Krzysztof Kozlowski
2022-06-27 11:46 ` Ilpo Järvinen
2022-06-27 12:39 ` Greg Kroah-Hartman
2 siblings, 0 replies; 6+ messages in thread
From: Krzysztof Kozlowski @ 2022-06-27 11:28 UTC (permalink / raw)
To: Chanho Park, Greg Kroah-Hartman
Cc: Jiri Slaby, Alim Akhtar, Hector Martin, Jaewon Kim,
Vincent Whitchurch, linux-samsung-soc, linux-serial,
linux-arm-kernel
On 27/06/2022 05:23, Chanho Park wrote:
> Internal loopback mode can be supported by setting
> S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
> s3c2410 and later SoCs. We can test it by linux-serial-test program[1]
> with -k option. It will set TIOCM_LOOP mode during test.
>
> -k, --loopback Use internal hardware loop back
>
> [1]: https://github.com/cbrake/linux-serial-test
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> ---
> drivers/tty/serial/samsung_tty.c | 19 ++++++++++++++++---
> 1 file changed, 16 insertions(+), 3 deletions(-)
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] tty: serial: samsung_tty: loopback mode support
2022-06-27 3:23 ` [PATCH] tty: serial: samsung_tty: loopback mode support Chanho Park
2022-06-27 11:28 ` Krzysztof Kozlowski
@ 2022-06-27 11:46 ` Ilpo Järvinen
2022-06-28 11:55 ` Chanho Park
2022-06-27 12:39 ` Greg Kroah-Hartman
2 siblings, 1 reply; 6+ messages in thread
From: Ilpo Järvinen @ 2022-06-27 11:46 UTC (permalink / raw)
To: Chanho Park
Cc: Krzysztof Kozlowski, Greg Kroah-Hartman, Jiri Slaby, Alim Akhtar,
Hector Martin, Jaewon Kim, Vincent Whitchurch, linux-samsung-soc,
linux-serial, linux-arm-kernel
On Mon, 27 Jun 2022, Chanho Park wrote:
> Internal loopback mode can be supported by setting
> S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
> s3c2410 and later SoCs.
In that case, why is the LOOPBACK define named 2443 and not 2410???
The change looks fine otherwise.
I note though that many of the current drivers won't return TOICM_LOOP
from ->get_mctrl() but I don't think it's exactly wrong to return it
either. Perhaps lack of returning it is due to
Documentation/driver-api/serial/driver.rst not including TOICM_LOOP in
get_mctrl's list of information but only in set_mctrl's one.
--
i.
> We can test it by linux-serial-test program[1]
> with -k option. It will set TIOCM_LOOP mode during test.
>
> -k, --loopback Use internal hardware loop back
>
> [1]: https://github.com/cbrake/linux-serial-test
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> ---
> drivers/tty/serial/samsung_tty.c | 19 ++++++++++++++++---
> 1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index d5ca904def34..d7d035cd95c0 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -1002,16 +1002,22 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
> static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
> {
> unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);
> + unsigned int ucon = rd_reg(port, S3C2410_UCON);
> + unsigned int mctrl = TIOCM_CAR | TIOCM_DSR;
>
> if (umstat & S3C2410_UMSTAT_CTS)
> - return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
> - else
> - return TIOCM_CAR | TIOCM_DSR;
> + mctrl |= TIOCM_CTS;
> +
> + if (ucon & S3C2443_UCON_LOOPBACK)
> + mctrl |= TIOCM_LOOP;
> +
> + return mctrl;
> }
>
> static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
> {
> unsigned int umcon = rd_regl(port, S3C2410_UMCON);
> + unsigned int ucon = rd_reg(port, S3C2410_UCON);
>
> if (mctrl & TIOCM_RTS)
> umcon |= S3C2410_UMCOM_RTS_LOW;
> @@ -1019,6 +1025,13 @@ static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
> umcon &= ~S3C2410_UMCOM_RTS_LOW;
>
> wr_regl(port, S3C2410_UMCON, umcon);
> +
> + if (mctrl & TIOCM_LOOP)
> + ucon |= S3C2443_UCON_LOOPBACK;
> + else
> + ucon &= ~S3C2443_UCON_LOOPBACK;
> +
> + wr_regl(port, S3C2410_UCON, ucon);
> }
>
> static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
>
^ permalink raw reply [flat|nested] 6+ messages in thread* RE: [PATCH] tty: serial: samsung_tty: loopback mode support
2022-06-27 11:46 ` Ilpo Järvinen
@ 2022-06-28 11:55 ` Chanho Park
0 siblings, 0 replies; 6+ messages in thread
From: Chanho Park @ 2022-06-28 11:55 UTC (permalink / raw)
To: 'Ilpo Järvinen'
Cc: 'Krzysztof Kozlowski', 'Greg Kroah-Hartman',
'Jiri Slaby', 'Alim Akhtar',
'Hector Martin', 'Jaewon Kim',
'Vincent Whitchurch', linux-samsung-soc,
'linux-serial', linux-arm-kernel
> Subject: Re: [PATCH] tty: serial: samsung_tty: loopback mode support
>
> On Mon, 27 Jun 2022, Chanho Park wrote:
>
> > Internal loopback mode can be supported by setting
> > S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
> > s3c2410 and later SoCs.
>
> In that case, why is the LOOPBACK define named 2443 and not 2410???
It might be copied from mach-s3c24xx.
>
> The change looks fine otherwise.
>
> I note though that many of the current drivers won't return TOICM_LOOP
> from ->get_mctrl() but I don't think it's exactly wrong to return it
> either. Perhaps lack of returning it is due to Documentation/driver-
> api/serial/driver.rst not including TOICM_LOOP in get_mctrl's list of
> information but only in set_mctrl's one.
According to the description, TIOCM_LOOP bit might be used only for setting.
I'll drop the bit manipulation from get_mctrl callback.
Thanks for the heads up.
Best Regards,
Chanho Park
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] tty: serial: samsung_tty: loopback mode support
2022-06-27 3:23 ` [PATCH] tty: serial: samsung_tty: loopback mode support Chanho Park
2022-06-27 11:28 ` Krzysztof Kozlowski
2022-06-27 11:46 ` Ilpo Järvinen
@ 2022-06-27 12:39 ` Greg Kroah-Hartman
2022-06-28 4:49 ` Chanho Park
2 siblings, 1 reply; 6+ messages in thread
From: Greg Kroah-Hartman @ 2022-06-27 12:39 UTC (permalink / raw)
To: Chanho Park
Cc: Krzysztof Kozlowski, Jiri Slaby, Alim Akhtar, Hector Martin,
Jaewon Kim, Vincent Whitchurch, linux-samsung-soc, linux-serial,
linux-arm-kernel
On Mon, Jun 27, 2022 at 12:23:53PM +0900, Chanho Park wrote:
> Internal loopback mode can be supported by setting
> S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
> s3c2410 and later SoCs. We can test it by linux-serial-test program[1]
> with -k option. It will set TIOCM_LOOP mode during test.
>
> -k, --loopback Use internal hardware loop back
I do not understand this line in the changelog text, what is it for?
>
> [1]: https://github.com/cbrake/linux-serial-test
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Our tools require a blank line before the signed-off-by line. Did you
not get a warning when checking this patch before sending it out?
Also, no need for a footnote in a changelog that is so short, just put
the link in the body of the text itself.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH] tty: serial: samsung_tty: loopback mode support
2022-06-27 12:39 ` Greg Kroah-Hartman
@ 2022-06-28 4:49 ` Chanho Park
0 siblings, 0 replies; 6+ messages in thread
From: Chanho Park @ 2022-06-28 4:49 UTC (permalink / raw)
To: 'Greg Kroah-Hartman'
Cc: 'Krzysztof Kozlowski', 'Jiri Slaby',
'Alim Akhtar', 'Hector Martin',
'Jaewon Kim', 'Vincent Whitchurch',
linux-samsung-soc, linux-serial, linux-arm-kernel
> Subject: Re: [PATCH] tty: serial: samsung_tty: loopback mode support
>
> On Mon, Jun 27, 2022 at 12:23:53PM +0900, Chanho Park wrote:
> > Internal loopback mode can be supported by setting
> > S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since
> > s3c2410 and later SoCs. We can test it by linux-serial-test program[1]
> > with -k option. It will set TIOCM_LOOP mode during test.
> >
> > -k, --loopback Use internal hardware loop back
>
> I do not understand this line in the changelog text, what is it for?
Ah. I'd like to show the option of linux-serial-test tool how we can test
it.
>
> >
> > [1]:
> > https://protect2.fireeye.com/v1/url?k=a0d4e46c-c15ff149-a0d56f23-74fe4
> > 85cbff6-c2c20e5c0d4f5c92&q=1&e=7c91006c-af87-4dad-8069-360450d31b36&u=
> > https%3A%2F%2Fgithub.com%2Fcbrake%2Flinux-serial-test
> > Signed-off-by: Chanho Park <chanho61.park@samsung.com>
>
> Our tools require a blank line before the signed-off-by line. Did you not
> get a warning when checking this patch before sending it out?
I'm able to see below warning. I'll fix it. Thanks.
WARNING: Do not use whitespace before Signed-off-by:
#15:
>
> Also, no need for a footnote in a changelog that is so short, just put the
> link in the body of the text itself.
Okay. I'll put the link in the body instead of the footnote.
Best Regards,
Chanho Park
^ permalink raw reply [flat|nested] 6+ messages in thread