* [PATCH] ata: pata_ep93xx: add missing "cc" clobber to inline asm
@ 2026-06-01 18:34 Rosen Penev
2026-07-20 21:09 ` Rosen Penev
0 siblings, 1 reply; 3+ messages in thread
From: Rosen Penev @ 2026-06-01 18:34 UTC (permalink / raw)
To: linux-ide; +Cc: Damien Le Moal, Niklas Cassel, open list
The inline assembly in ep93xx_pata_delay() uses a "subs" instruction
which modifies the ARM condition code flags. Add a "cc" clobber so
the compiler knows the flags are altered. Without it, the compiler may
reorder flag-dependent instructions across the asm block when the
function is inlined, potentially causing incorrect control flow.
Assisted-by: Opencode:Big-Pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
drivers/ata/pata_ep93xx.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/ata/pata_ep93xx.c b/drivers/ata/pata_ep93xx.c
index aa6f8172925d..838cab54d58a 100644
--- a/drivers/ata/pata_ep93xx.c
+++ b/drivers/ata/pata_ep93xx.c
@@ -211,6 +211,7 @@ static void ep93xx_pata_delay(unsigned long count)
"bge 0b\n"
: "=r" (count)
: "0" (count)
+ : "cc"
);
}
--
2.54.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ata: pata_ep93xx: add missing "cc" clobber to inline asm
2026-06-01 18:34 [PATCH] ata: pata_ep93xx: add missing "cc" clobber to inline asm Rosen Penev
@ 2026-07-20 21:09 ` Rosen Penev
2026-07-20 23:02 ` Damien Le Moal
0 siblings, 1 reply; 3+ messages in thread
From: Rosen Penev @ 2026-07-20 21:09 UTC (permalink / raw)
To: linux-ide; +Cc: Damien Le Moal, Niklas Cassel, open list
On Mon, Jun 1, 2026 at 11:35 AM Rosen Penev <rosenp@gmail.com> wrote:
>
> The inline assembly in ep93xx_pata_delay() uses a "subs" instruction
> which modifies the ARM condition code flags. Add a "cc" clobber so
> the compiler knows the flags are altered. Without it, the compiler may
> reorder flag-dependent instructions across the asm block when the
> function is inlined, potentially causing incorrect control flow.
>
> Assisted-by: Opencode:Big-Pickle
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
should I resend?
> ---
> drivers/ata/pata_ep93xx.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/ata/pata_ep93xx.c b/drivers/ata/pata_ep93xx.c
> index aa6f8172925d..838cab54d58a 100644
> --- a/drivers/ata/pata_ep93xx.c
> +++ b/drivers/ata/pata_ep93xx.c
> @@ -211,6 +211,7 @@ static void ep93xx_pata_delay(unsigned long count)
> "bge 0b\n"
> : "=r" (count)
> : "0" (count)
> + : "cc"
> );
> }
>
> --
> 2.54.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ata: pata_ep93xx: add missing "cc" clobber to inline asm
2026-07-20 21:09 ` Rosen Penev
@ 2026-07-20 23:02 ` Damien Le Moal
0 siblings, 0 replies; 3+ messages in thread
From: Damien Le Moal @ 2026-07-20 23:02 UTC (permalink / raw)
To: Rosen Penev, linux-ide; +Cc: Niklas Cassel, open list
On 7/21/26 06:09, Rosen Penev wrote:
> On Mon, Jun 1, 2026 at 11:35 AM Rosen Penev <rosenp@gmail.com> wrote:
>>
>> The inline assembly in ep93xx_pata_delay() uses a "subs" instruction
>> which modifies the ARM condition code flags. Add a "cc" clobber so
>> the compiler knows the flags are altered. Without it, the compiler may
>> reorder flag-dependent instructions across the asm block when the
>> function is inlined, potentially causing incorrect control flow.
>>
>> Assisted-by: Opencode:Big-Pickle
>> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> should I resend?
Oops. This fell through the cracks. Yes, please resend and add a fixes tag as well.
--
Damien Le Moal
Western Digital Research
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-06-01 18:34 [PATCH] ata: pata_ep93xx: add missing "cc" clobber to inline asm Rosen Penev
2026-07-20 21:09 ` Rosen Penev
2026-07-20 23:02 ` Damien Le Moal
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