delay: Fix ndelay() spuriously treated as udelay()

[PATCH] delay: Fix ndelay() spuriously treated as udelay()

Posted by Frederic Weisbecker 1 year, 2 months ago

A recent rework on delay functions wrongly ended up calling __udelay()
instead of __ndelay() for nanosecond delays, increasing those by 1000.

As a result hangs have been observed on boot

Restore the right function calls.

Fixes: 19e2d91d8cb1 ("delay: Rework udelay and ndelay")
Reported-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
 include/asm-generic/delay.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h
index 76cf237b6e4c..03b0ec7afca6 100644
--- a/include/asm-generic/delay.h
+++ b/include/asm-generic/delay.h
@@ -75,11 +75,11 @@ static __always_inline void ndelay(unsigned long nsec)
 {
 	if (__builtin_constant_p(nsec)) {
 		if (nsec >= DELAY_CONST_MAX)
-			__bad_udelay();
+			__bad_ndelay();
 		else
 			__const_udelay(nsec * NDELAY_CONST_MULT);
 	} else {
-		__udelay(nsec);
+		__ndelay(nsec);
 	}
 }
 #define ndelay(x) ndelay(x)
-- 
2.46.0

Re: [PATCH] delay: Fix ndelay() spuriously treated as udelay()

Posted by Nícolas F. R. A. Prado 1 year, 2 months ago

On Thu, Nov 21, 2024 at 04:29:31PM +0100, Frederic Weisbecker wrote:
> A recent rework on delay functions wrongly ended up calling __udelay()
> instead of __ndelay() for nanosecond delays, increasing those by 1000.
> 
> As a result hangs have been observed on boot
> 
> Restore the right function calls.
> 
> Fixes: 19e2d91d8cb1 ("delay: Rework udelay and ndelay")
> Reported-by: Chen-Yu Tsai <wenst@chromium.org>
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

It's possible to boot again on MT8195-Cherry-Tomato with this patch applied on
top of next-20241128.

Thanks,
Nícolas

Re: [PATCH] delay: Fix ndelay() spuriously treated as udelay()

Posted by AngeloGioacchino Del Regno 1 year, 2 months ago

Il 21/11/24 16:29, Frederic Weisbecker ha scritto:
> A recent rework on delay functions wrongly ended up calling __udelay()
> instead of __ndelay() for nanosecond delays, increasing those by 1000.
> 
> As a result hangs have been observed on boot
> 
> Restore the right function calls.
> 
> Fixes: 19e2d91d8cb1 ("delay: Rework udelay and ndelay")
> Reported-by: Chen-Yu Tsai <wenst@chromium.org>
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Re: [PATCH] delay: Fix ndelay() spuriously treated as udelay()

Posted by Chen-Yu Tsai 1 year, 2 months ago

On Thu, Nov 21, 2024 at 11:30 PM Frederic Weisbecker
<frederic@kernel.org> wrote:
>
> A recent rework on delay functions wrongly ended up calling __udelay()
> instead of __ndelay() for nanosecond delays, increasing those by 1000.
>
> As a result hangs have been observed on boot
>
> Restore the right function calls.
>
> Fixes: 19e2d91d8cb1 ("delay: Rework udelay and ndelay")
> Reported-by: Chen-Yu Tsai <wenst@chromium.org>
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

Thank you for the quick response! This fixed things for me.

> ---
>  include/asm-generic/delay.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h
> index 76cf237b6e4c..03b0ec7afca6 100644
> --- a/include/asm-generic/delay.h
> +++ b/include/asm-generic/delay.h
> @@ -75,11 +75,11 @@ static __always_inline void ndelay(unsigned long nsec)
>  {
>         if (__builtin_constant_p(nsec)) {
>                 if (nsec >= DELAY_CONST_MAX)
> -                       __bad_udelay();
> +                       __bad_ndelay();
>                 else
>                         __const_udelay(nsec * NDELAY_CONST_MULT);
>         } else {
> -               __udelay(nsec);
> +               __ndelay(nsec);
>         }
>  }
>  #define ndelay(x) ndelay(x)
> --
> 2.46.0
>

[tip: timers/urgent] delay: Fix ndelay() spuriously treated as udelay()

Posted by tip-bot2 for Frederic Weisbecker 1 year, 2 months ago

The following commit has been merged into the timers/urgent branch of tip:

Commit-ID:     4d17c25eaf5d8b95d70726e6946e8eb94619e139
Gitweb:        https://git.kernel.org/tip/4d17c25eaf5d8b95d70726e6946e8eb94619e139
Author:        Frederic Weisbecker <frederic@kernel.org>
AuthorDate:    Thu, 21 Nov 2024 16:29:31 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Fri, 29 Nov 2024 11:40:22 +01:00

delay: Fix ndelay() spuriously treated as udelay()

A recent rework on delay functions wrongly ended up calling __udelay()
instead of __ndelay() for nanosecond delays, increasing those by 1000.

As a result hangs have been observed on boot

Restore the right function calls.

Fixes: 19e2d91d8cb1 ("delay: Rework udelay and ndelay")
Reported-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/all/20241121152931.51884-1-frederic@kernel.org

---
 include/asm-generic/delay.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h
index 76cf237..03b0ec7 100644
--- a/include/asm-generic/delay.h
+++ b/include/asm-generic/delay.h
@@ -75,11 +75,11 @@ static __always_inline void ndelay(unsigned long nsec)
 {
 	if (__builtin_constant_p(nsec)) {
 		if (nsec >= DELAY_CONST_MAX)
-			__bad_udelay();
+			__bad_ndelay();
 		else
 			__const_udelay(nsec * NDELAY_CONST_MULT);
 	} else {
-		__udelay(nsec);
+		__ndelay(nsec);
 	}
 }
 #define ndelay(x) ndelay(x)