Hello Uwe,
Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> writes:
> Hello Sergey,
>
> On Fri, Jul 19, 2019 at 03:18:13PM +0300, Sergey Organov wrote:
>> Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> writes:
>> > On Fri, Jul 19, 2019 at 11:47:52AM +0300, Sergey Organov wrote:
>> >> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
>> >> index 57d6e6b..95d7984 100644
>> >> --- a/drivers/tty/serial/imx.c
>> >> +++ b/drivers/tty/serial/imx.c
>> >> @@ -405,7 +405,8 @@ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
>> >> /* called with port.lock taken and irqs caller dependent */
>> >> static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
>> >> {
>> >> - *ucr2 |= UCR2_CTSC;
>> >> + if (*ucr2 & UCR2_CTS)
>> >> + *ucr2 |= UCR2_CTSC;
>> >
>> > I think this patch is wrong or the commit log is insufficient.
>> > imx_uart_rts_auto() has only a single caller and there ucr2 & UCR2_CTS is
>> > never true. And CTSC isn't restored anywhere, is it?
>>
>> This is rebase to 'tty-next' branch, and you need to look at it in that
>> context. There, ucr2 & UCR2_CTS does already make sense, due to previous
>> fix that is already there.
>
> I looked at 57d6e6b which is the file you patched. And there
> imx_uart_rts_auto is only ever called with *ucr2 not having UCR2_CTS.
>
> If you still think I'm wrong, please improve the commit log
> accordingly.
I still think you are wrong, but I don't know how to improve commit log.
To check it once again, I just did:
$ git show 57d6e6b > imx.c
There, in imx_uart_set_termios(), I see:
1569: old_ucr2 = imx_uart_readl(sport, UCR2);
1570: ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
Here, current UCR2 value is read into 'old_ucr2' and then its /current/
UCR2_CTS bit is copied into 'ucr2' (along with 3 other bits).
Then, later in the same function:
1591: imx_uart_rts_auto(sport, &ucr2);
is called that can check /current/ state of UCR2_CTS bit in '*ucr2'.
That's what the patch does, checks this bit.
Sorry, I fail to see how you came to conclusion that "*ucr2 not having
UCR2_CTS". Do we maybe still read different versions of the file?
-- Sergey
