* [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in()
@ 2023-02-02 10:45 Uwe Kleine-König
2023-02-02 11:26 ` Ilpo Järvinen
0 siblings, 1 reply; 6+ messages in thread
From: Uwe Kleine-König @ 2023-02-02 10:45 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ilpo Järvinen
Cc: Andy Shevchenko, linux-serial, kernel
The relevant history introducing serial_lsr_in() looks as follows:
$ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c
* df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next
|\
| * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read
* | ...
* | bdb70c424df1 serial: 8250: Create serial_lsr_in()
* | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read
* | ...
|/
o 9fafe733514b tty: remove CMSPAR ifdefs
So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was
introduced twice and in one branch it was followed up by commit
bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved
explicit lsr_saved_flags handling into a new function serial_lsr_in().
When the two branches were merged in commit df36f3e3fbb7, we got both,
serial_lsr_in() and the explicit lsr_saved_flags handling.
So drop the explicit lsr_saved_flags handling.
Fixes: df36f3e3fbb7 ("Merge tag 'v5.19-rc3' into tty-next")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/tty/serial/8250/8250_port.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 33be7aad11ef..e61753c295d5 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1512,8 +1512,6 @@ static inline void __stop_tx(struct uart_8250_port *p)
u16 lsr = serial_lsr_in(p);
u64 stop_delay = 0;
- p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
-
if (!(lsr & UART_LSR_THRE))
return;
/*
--
2.39.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in()
2023-02-02 10:45 [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in() Uwe Kleine-König
@ 2023-02-02 11:26 ` Ilpo Järvinen
2023-02-02 12:04 ` Uwe Kleine-König
0 siblings, 1 reply; 6+ messages in thread
From: Ilpo Järvinen @ 2023-02-02 11:26 UTC (permalink / raw)
To: Uwe Kleine-König
Cc: Greg Kroah-Hartman, Andy Shevchenko, linux-serial, kernel
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On Thu, 2 Feb 2023, Uwe Kleine-König wrote:
> The relevant history introducing serial_lsr_in() looks as follows:
>
> $ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c
> * df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next
> |\
> | * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read
> * | ...
> * | bdb70c424df1 serial: 8250: Create serial_lsr_in()
> * | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read
> * | ...
> |/
> o 9fafe733514b tty: remove CMSPAR ifdefs
>
> So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was
> introduced twice and in one branch it was followed up by commit
> bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved
> explicit lsr_saved_flags handling into a new function serial_lsr_in().
> When the two branches were merged in commit df36f3e3fbb7, we got both,
> serial_lsr_in() and the explicit lsr_saved_flags handling.
>
> So drop the explicit lsr_saved_flags handling.
>
> Fixes: df36f3e3fbb7 ("Merge tag 'v5.19-rc3' into tty-next")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> drivers/tty/serial/8250/8250_port.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index 33be7aad11ef..e61753c295d5 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -1512,8 +1512,6 @@ static inline void __stop_tx(struct uart_8250_port *p)
> u16 lsr = serial_lsr_in(p);
> u64 stop_delay = 0;
>
> - p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
> -
> if (!(lsr & UART_LSR_THRE))
> return;
> /*
I don't know if Fixes tag is appropriate here. This fixes the mismerge
yes, however, the removed line itself seems harmless so there's no real
problem to fix.
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
--
i.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in()
2023-02-02 11:26 ` Ilpo Järvinen
@ 2023-02-02 12:04 ` Uwe Kleine-König
2023-02-02 12:09 ` Ilpo Järvinen
0 siblings, 1 reply; 6+ messages in thread
From: Uwe Kleine-König @ 2023-02-02 12:04 UTC (permalink / raw)
To: Ilpo Järvinen
Cc: Greg Kroah-Hartman, Andy Shevchenko, kernel, linux-serial
[-- Attachment #1: Type: text/plain, Size: 2337 bytes --]
On Thu, Feb 02, 2023 at 01:26:08PM +0200, Ilpo Järvinen wrote:
> On Thu, 2 Feb 2023, Uwe Kleine-König wrote:
>
> > The relevant history introducing serial_lsr_in() looks as follows:
> >
> > $ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c
> > * df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next
> > |\
> > | * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read
> > * | ...
> > * | bdb70c424df1 serial: 8250: Create serial_lsr_in()
> > * | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read
> > * | ...
> > |/
> > o 9fafe733514b tty: remove CMSPAR ifdefs
> >
> > So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was
> > introduced twice and in one branch it was followed up by commit
> > bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved
> > explicit lsr_saved_flags handling into a new function serial_lsr_in().
> > When the two branches were merged in commit df36f3e3fbb7, we got both,
> > serial_lsr_in() and the explicit lsr_saved_flags handling.
> >
> > So drop the explicit lsr_saved_flags handling.
> >
> > Fixes: df36f3e3fbb7 ("Merge tag 'v5.19-rc3' into tty-next")
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > ---
> > drivers/tty/serial/8250/8250_port.c | 2 --
> > 1 file changed, 2 deletions(-)
> >
> > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> > index 33be7aad11ef..e61753c295d5 100644
> > --- a/drivers/tty/serial/8250/8250_port.c
> > +++ b/drivers/tty/serial/8250/8250_port.c
> > @@ -1512,8 +1512,6 @@ static inline void __stop_tx(struct uart_8250_port *p)
> > u16 lsr = serial_lsr_in(p);
> > u64 stop_delay = 0;
> >
> > - p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
> > -
> > if (!(lsr & UART_LSR_THRE))
> > return;
> > /*
>
> I don't know if Fixes tag is appropriate here. This fixes the mismerge
> yes, however, the removed line itself seems harmless so there's no real
> problem to fix.
It might make a difference if LSR_SAVE_FLAGS != p->lsr_save_mask.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in()
2023-02-02 12:04 ` Uwe Kleine-König
@ 2023-02-02 12:09 ` Ilpo Järvinen
2023-02-02 13:40 ` Uwe Kleine-König
0 siblings, 1 reply; 6+ messages in thread
From: Ilpo Järvinen @ 2023-02-02 12:09 UTC (permalink / raw)
To: Uwe Kleine-König
Cc: Greg Kroah-Hartman, Andy Shevchenko, kernel, linux-serial
[-- Attachment #1: Type: text/plain, Size: 2352 bytes --]
On Thu, 2 Feb 2023, Uwe Kleine-König wrote:
> On Thu, Feb 02, 2023 at 01:26:08PM +0200, Ilpo Järvinen wrote:
> > On Thu, 2 Feb 2023, Uwe Kleine-König wrote:
> >
> > > The relevant history introducing serial_lsr_in() looks as follows:
> > >
> > > $ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c
> > > * df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next
> > > |\
> > > | * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read
> > > * | ...
> > > * | bdb70c424df1 serial: 8250: Create serial_lsr_in()
> > > * | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read
> > > * | ...
> > > |/
> > > o 9fafe733514b tty: remove CMSPAR ifdefs
> > >
> > > So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was
> > > introduced twice and in one branch it was followed up by commit
> > > bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved
> > > explicit lsr_saved_flags handling into a new function serial_lsr_in().
> > > When the two branches were merged in commit df36f3e3fbb7, we got both,
> > > serial_lsr_in() and the explicit lsr_saved_flags handling.
> > >
> > > So drop the explicit lsr_saved_flags handling.
> > >
> > > Fixes: df36f3e3fbb7 ("Merge tag 'v5.19-rc3' into tty-next")
> > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > > ---
> > > drivers/tty/serial/8250/8250_port.c | 2 --
> > > 1 file changed, 2 deletions(-)
> > >
> > > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> > > index 33be7aad11ef..e61753c295d5 100644
> > > --- a/drivers/tty/serial/8250/8250_port.c
> > > +++ b/drivers/tty/serial/8250/8250_port.c
> > > @@ -1512,8 +1512,6 @@ static inline void __stop_tx(struct uart_8250_port *p)
> > > u16 lsr = serial_lsr_in(p);
> > > u64 stop_delay = 0;
> > >
> > > - p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
> > > -
> > > if (!(lsr & UART_LSR_THRE))
> > > return;
> > > /*
> >
> > I don't know if Fixes tag is appropriate here. This fixes the mismerge
> > yes, however, the removed line itself seems harmless so there's no real
> > problem to fix.
>
> It might make a difference if LSR_SAVE_FLAGS != p->lsr_save_mask.
But currently lsr_save_mask always has at least LSR_SAVE_FLAGS bits so
that OR is no-op.
--
i.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in()
2023-02-02 12:09 ` Ilpo Järvinen
@ 2023-02-02 13:40 ` Uwe Kleine-König
2023-02-02 13:59 ` Greg Kroah-Hartman
0 siblings, 1 reply; 6+ messages in thread
From: Uwe Kleine-König @ 2023-02-02 13:40 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ilpo Järvinen
Cc: Andy Shevchenko, linux-serial, kernel
[-- Attachment #1: Type: text/plain, Size: 891 bytes --]
Hello Ilpo,
On Thu, Feb 02, 2023 at 02:09:38PM +0200, Ilpo Järvinen wrote:
> On Thu, 2 Feb 2023, Uwe Kleine-König wrote:
> > On Thu, Feb 02, 2023 at 01:26:08PM +0200, Ilpo Järvinen wrote:
> > > I don't know if Fixes tag is appropriate here. This fixes the mismerge
> > > yes, however, the removed line itself seems harmless so there's no real
> > > problem to fix.
> >
> > It might make a difference if LSR_SAVE_FLAGS != p->lsr_save_mask.
>
> But currently lsr_save_mask always has at least LSR_SAVE_FLAGS bits so
> that OR is no-op.
Oh indeed. So it's even more harmless than I thought. Thanks.
@gregkh: I don't feel strong about the Fixes line, drop it if you prefer
to not have it.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in()
2023-02-02 13:40 ` Uwe Kleine-König
@ 2023-02-02 13:59 ` Greg Kroah-Hartman
0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2023-02-02 13:59 UTC (permalink / raw)
To: Uwe Kleine-König
Cc: Ilpo Järvinen, Andy Shevchenko, linux-serial, kernel
On Thu, Feb 02, 2023 at 02:40:57PM +0100, Uwe Kleine-König wrote:
> Hello Ilpo,
>
> On Thu, Feb 02, 2023 at 02:09:38PM +0200, Ilpo Järvinen wrote:
> > On Thu, 2 Feb 2023, Uwe Kleine-König wrote:
> > > On Thu, Feb 02, 2023 at 01:26:08PM +0200, Ilpo Järvinen wrote:
> > > > I don't know if Fixes tag is appropriate here. This fixes the mismerge
> > > > yes, however, the removed line itself seems harmless so there's no real
> > > > problem to fix.
> > >
> > > It might make a difference if LSR_SAVE_FLAGS != p->lsr_save_mask.
> >
> > But currently lsr_save_mask always has at least LSR_SAVE_FLAGS bits so
> > that OR is no-op.
>
> Oh indeed. So it's even more harmless than I thought. Thanks.
>
> @gregkh: I don't feel strong about the Fixes line, drop it if you prefer
> to not have it.
I'll drop it, thanks!
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-02-02 13:59 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-02 10:45 [PATCH] serial: 8250: Fix mismerge regarding serial_lsr_in() Uwe Kleine-König
2023-02-02 11:26 ` Ilpo Järvinen
2023-02-02 12:04 ` Uwe Kleine-König
2023-02-02 12:09 ` Ilpo Järvinen
2023-02-02 13:40 ` Uwe Kleine-König
2023-02-02 13:59 ` Greg Kroah-Hartman
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