* [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-08 4:32 ` Anand K Mistry
0 siblings, 0 replies; 9+ messages in thread
From: Anand K Mistry @ 2021-06-08 4:32 UTC (permalink / raw)
To: amd-gfx
Cc: Anand K Mistry, Alex Deucher, Aurabindo Pillai,
Bas Nieuwenhuizen, Christian König, Daniel Vetter,
David Airlie, Eryk Brol, Harry Wentland, Leo Li,
Nicholas Kazlauskas, Nikola Cornij, Qingqing Zhuo,
Rodrigo Siqueira, Wayne Lin, dri-devel, linux-kernel
The backlight_ops.update_status function is required to return a
negative error code on failure. Returning a positive code may be
interpreted as a success. This is true for the 'brightness' sysfs file,
which passes through a non-zero value as the return value of the write()
syscall. This is interpreted in user-space as a successful write of 1
character, which is obviously wrong.
It's not clear exactly what error code to use, but EINVAL should be
reasonable.
Signed-off-by: Anand K Mistry <amistry@google.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 652cc1a0e450..ad322613390d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3431,7 +3431,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
else
rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
- return rc ? 0 : 1;
+ return rc ? 0 : -EINVAL;
}
static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
--
2.32.0.rc1.229.g3e70b5a671-goog
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-08 4:32 ` Anand K Mistry
0 siblings, 0 replies; 9+ messages in thread
From: Anand K Mistry @ 2021-06-08 4:32 UTC (permalink / raw)
To: amd-gfx
Cc: Anand K Mistry, Eryk Brol, David Airlie, Qingqing Zhuo,
Wayne Lin, Rodrigo Siqueira, linux-kernel, dri-devel,
Nicholas Kazlauskas, Leo Li, Aurabindo Pillai, Daniel Vetter,
Bas Nieuwenhuizen, Alex Deucher, Nikola Cornij, Harry Wentland,
Christian König
The backlight_ops.update_status function is required to return a
negative error code on failure. Returning a positive code may be
interpreted as a success. This is true for the 'brightness' sysfs file,
which passes through a non-zero value as the return value of the write()
syscall. This is interpreted in user-space as a successful write of 1
character, which is obviously wrong.
It's not clear exactly what error code to use, but EINVAL should be
reasonable.
Signed-off-by: Anand K Mistry <amistry@google.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 652cc1a0e450..ad322613390d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3431,7 +3431,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
else
rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
- return rc ? 0 : 1;
+ return rc ? 0 : -EINVAL;
}
static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
--
2.32.0.rc1.229.g3e70b5a671-goog
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-08 4:32 ` Anand K Mistry
0 siblings, 0 replies; 9+ messages in thread
From: Anand K Mistry @ 2021-06-08 4:32 UTC (permalink / raw)
To: amd-gfx
Cc: Anand K Mistry, Eryk Brol, David Airlie, Qingqing Zhuo,
Wayne Lin, Rodrigo Siqueira, linux-kernel, dri-devel,
Nicholas Kazlauskas, Leo Li, Aurabindo Pillai, Alex Deucher,
Nikola Cornij, Christian König
The backlight_ops.update_status function is required to return a
negative error code on failure. Returning a positive code may be
interpreted as a success. This is true for the 'brightness' sysfs file,
which passes through a non-zero value as the return value of the write()
syscall. This is interpreted in user-space as a successful write of 1
character, which is obviously wrong.
It's not clear exactly what error code to use, but EINVAL should be
reasonable.
Signed-off-by: Anand K Mistry <amistry@google.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 652cc1a0e450..ad322613390d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3431,7 +3431,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
else
rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
- return rc ? 0 : 1;
+ return rc ? 0 : -EINVAL;
}
static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
--
2.32.0.rc1.229.g3e70b5a671-goog
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] drm/amd/display: Fix error code on failure to set brightness
2021-06-08 4:32 ` Anand K Mistry
(?)
@ 2021-06-08 13:59 ` Harry Wentland
-1 siblings, 0 replies; 9+ messages in thread
From: Harry Wentland @ 2021-06-08 13:59 UTC (permalink / raw)
To: Anand K Mistry, amd-gfx
Cc: Alex Deucher, Aurabindo Pillai, Bas Nieuwenhuizen,
Christian König, Daniel Vetter, David Airlie, Eryk Brol,
Leo Li, Nicholas Kazlauskas, Nikola Cornij, Qingqing Zhuo,
Rodrigo Siqueira, Wayne Lin, dri-devel, linux-kernel
On 2021-06-08 12:32 a.m., Anand K Mistry wrote:
> The backlight_ops.update_status function is required to return a
> negative error code on failure. Returning a positive code may be
> interpreted as a success. This is true for the 'brightness' sysfs file,
> which passes through a non-zero value as the return value of the write()
> syscall. This is interpreted in user-space as a successful write of 1
> character, which is obviously wrong.
>
> It's not clear exactly what error code to use, but EINVAL should be
> reasonable.
>
> Signed-off-by: Anand K Mistry <amistry@google.com>
Thanks for your patch but this code has changed on amd-staging-drm-next.
Can you try with the latest? The new backlight_update_status will always
return 0 now.
Harry
> ---
>
> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 652cc1a0e450..ad322613390d 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3431,7 +3431,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
> else
> rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
>
> - return rc ? 0 : 1;
> + return rc ? 0 : -EINVAL;
> }
>
> static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-08 13:59 ` Harry Wentland
0 siblings, 0 replies; 9+ messages in thread
From: Harry Wentland @ 2021-06-08 13:59 UTC (permalink / raw)
To: Anand K Mistry, amd-gfx
Cc: Eryk Brol, David Airlie, Qingqing Zhuo, Wayne Lin,
Rodrigo Siqueira, linux-kernel, dri-devel, Nicholas Kazlauskas,
Leo Li, Aurabindo Pillai, Daniel Vetter, Bas Nieuwenhuizen,
Alex Deucher, Nikola Cornij, Christian König
On 2021-06-08 12:32 a.m., Anand K Mistry wrote:
> The backlight_ops.update_status function is required to return a
> negative error code on failure. Returning a positive code may be
> interpreted as a success. This is true for the 'brightness' sysfs file,
> which passes through a non-zero value as the return value of the write()
> syscall. This is interpreted in user-space as a successful write of 1
> character, which is obviously wrong.
>
> It's not clear exactly what error code to use, but EINVAL should be
> reasonable.
>
> Signed-off-by: Anand K Mistry <amistry@google.com>
Thanks for your patch but this code has changed on amd-staging-drm-next.
Can you try with the latest? The new backlight_update_status will always
return 0 now.
Harry
> ---
>
> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 652cc1a0e450..ad322613390d 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3431,7 +3431,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
> else
> rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
>
> - return rc ? 0 : 1;
> + return rc ? 0 : -EINVAL;
> }
>
> static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
>
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-08 13:59 ` Harry Wentland
0 siblings, 0 replies; 9+ messages in thread
From: Harry Wentland @ 2021-06-08 13:59 UTC (permalink / raw)
To: Anand K Mistry, amd-gfx
Cc: Eryk Brol, David Airlie, Qingqing Zhuo, Wayne Lin,
Rodrigo Siqueira, linux-kernel, dri-devel, Nicholas Kazlauskas,
Leo Li, Aurabindo Pillai, Alex Deucher, Nikola Cornij,
Christian König
On 2021-06-08 12:32 a.m., Anand K Mistry wrote:
> The backlight_ops.update_status function is required to return a
> negative error code on failure. Returning a positive code may be
> interpreted as a success. This is true for the 'brightness' sysfs file,
> which passes through a non-zero value as the return value of the write()
> syscall. This is interpreted in user-space as a successful write of 1
> character, which is obviously wrong.
>
> It's not clear exactly what error code to use, but EINVAL should be
> reasonable.
>
> Signed-off-by: Anand K Mistry <amistry@google.com>
Thanks for your patch but this code has changed on amd-staging-drm-next.
Can you try with the latest? The new backlight_update_status will always
return 0 now.
Harry
> ---
>
> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 652cc1a0e450..ad322613390d 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3431,7 +3431,7 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
> else
> rc = dc_link_set_backlight_level(dm->backlight_link, brightness, 0);
>
> - return rc ? 0 : 1;
> + return rc ? 0 : -EINVAL;
> }
>
> static int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd)
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drm/amd/display: Fix error code on failure to set brightness
2021-06-08 13:59 ` Harry Wentland
(?)
@ 2021-06-09 0:55 ` Anand K. Mistry
-1 siblings, 0 replies; 9+ messages in thread
From: Anand K. Mistry @ 2021-06-09 0:55 UTC (permalink / raw)
To: Harry Wentland
Cc: amd-gfx, Alex Deucher, Aurabindo Pillai, Bas Nieuwenhuizen,
Christian König, Daniel Vetter, David Airlie, Eryk Brol,
Leo Li, Nicholas Kazlauskas, Nikola Cornij, Qingqing Zhuo,
Rodrigo Siqueira, Wayne Lin, DRI Development,
Linux Kernel Mailing List
>
> Thanks for your patch but this code has changed on amd-staging-drm-next.
>
> Can you try with the latest? The new backlight_update_status will always
> return 0 now.
Perfect! This solves my actual issue which is that restoring the
backlight level is failing on my device. Thank you.
--
Anand K. Mistry
Software Engineer
Google Australia
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-09 0:55 ` Anand K. Mistry
0 siblings, 0 replies; 9+ messages in thread
From: Anand K. Mistry @ 2021-06-09 0:55 UTC (permalink / raw)
To: Harry Wentland
Cc: Eryk Brol, David Airlie, Qingqing Zhuo, Wayne Lin,
Rodrigo Siqueira, Linux Kernel Mailing List, amd-gfx,
Nicholas Kazlauskas, Leo Li, Aurabindo Pillai, DRI Development,
Daniel Vetter, Bas Nieuwenhuizen, Alex Deucher, Nikola Cornij,
Christian König
>
> Thanks for your patch but this code has changed on amd-staging-drm-next.
>
> Can you try with the latest? The new backlight_update_status will always
> return 0 now.
Perfect! This solves my actual issue which is that restoring the
backlight level is failing on my device. Thank you.
--
Anand K. Mistry
Software Engineer
Google Australia
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drm/amd/display: Fix error code on failure to set brightness
@ 2021-06-09 0:55 ` Anand K. Mistry
0 siblings, 0 replies; 9+ messages in thread
From: Anand K. Mistry @ 2021-06-09 0:55 UTC (permalink / raw)
To: Harry Wentland
Cc: Eryk Brol, David Airlie, Qingqing Zhuo, Wayne Lin,
Rodrigo Siqueira, Linux Kernel Mailing List, amd-gfx,
Nicholas Kazlauskas, Leo Li, Aurabindo Pillai, DRI Development,
Alex Deucher, Nikola Cornij, Christian König
>
> Thanks for your patch but this code has changed on amd-staging-drm-next.
>
> Can you try with the latest? The new backlight_update_status will always
> return 0 now.
Perfect! This solves my actual issue which is that restoring the
backlight level is failing on my device. Thank you.
--
Anand K. Mistry
Software Engineer
Google Australia
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2021-06-09 1:04 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-08 4:32 [PATCH] drm/amd/display: Fix error code on failure to set brightness Anand K Mistry
2021-06-08 4:32 ` Anand K Mistry
2021-06-08 4:32 ` Anand K Mistry
2021-06-08 13:59 ` Harry Wentland
2021-06-08 13:59 ` Harry Wentland
2021-06-08 13:59 ` Harry Wentland
2021-06-09 0:55 ` Anand K. Mistry
2021-06-09 0:55 ` Anand K. Mistry
2021-06-09 0:55 ` Anand K. Mistry
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