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| author | Arun R Murthy <arun.r.murthy@intel.com> | 2022-08-08 09:27:50 +0530 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2022-08-29 10:00:41 -0400 |
| commit | 2c4e19f873f4a389c2a557a84909cf4b78d3525a (patch) | |
| tree | fbc7f0ae9df2925ee3e55a48eea8939703a7d39a /drivers/gpu/drm/i915 | |
| parent | 875c6d2711f6c97e58c52288b4231f3072711d61 (diff) | |
| download | linux-2c4e19f873f4a389c2a557a84909cf4b78d3525a.tar.gz linux-2c4e19f873f4a389c2a557a84909cf4b78d3525a.tar.bz2 linux-2c4e19f873f4a389c2a557a84909cf4b78d3525a.zip | |
drm/i915/display: avoid warnings when registering dual panel backlight
Commit 20f85ef89d94 ("drm/i915/backlight: use unique backlight device
names") added support for multiple backlight devices on dual panel
systems, but did so with error handling on -EEXIST from
backlight_device_register(). Unfortunately, that triggered a warning in
dmesg all the way down from sysfs_add_file_mode_ns() and
sysfs_warn_dup().
Instead of optimistically always attempting to register with the default
name ("intel_backlight", which we have to retain for backward
compatibility), check if a backlight device with the name exists first,
and, if so, use the card and connector based name.
v2: reworked on top of the patch commit 20f85ef89d94
("drm/i915/backlight: use unique backlight device names")
v3: fixed the ref count leak(Jani N)
Fixes: 20f85ef89d94 ("drm/i915/backlight: use unique backlight device names")
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808035750.3111046-1-arun.r.murthy@intel.com
(cherry picked from commit 4234ea30051200fc6016de10e4d58369e60b38f1)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_backlight.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c index 110fc98ec280..931446413372 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -971,26 +971,24 @@ int intel_backlight_device_register(struct intel_connector *connector) if (!name) return -ENOMEM; - bd = backlight_device_register(name, connector->base.kdev, connector, - &intel_backlight_device_ops, &props); - - /* - * Using the same name independent of the drm device or connector - * prevents registration of multiple backlight devices in the - * driver. However, we need to use the default name for backward - * compatibility. Use unique names for subsequent backlight devices as a - * fallback when the default name already exists. - */ - if (IS_ERR(bd) && PTR_ERR(bd) == -EEXIST) { + bd = backlight_device_get_by_name(name); + if (bd) { + put_device(&bd->dev); + /* + * Using the same name independent of the drm device or connector + * prevents registration of multiple backlight devices in the + * driver. However, we need to use the default name for backward + * compatibility. Use unique names for subsequent backlight devices as a + * fallback when the default name already exists. + */ kfree(name); name = kasprintf(GFP_KERNEL, "card%d-%s-backlight", i915->drm.primary->index, connector->base.name); if (!name) return -ENOMEM; - - bd = backlight_device_register(name, connector->base.kdev, connector, - &intel_backlight_device_ops, &props); } + bd = backlight_device_register(name, connector->base.kdev, connector, + &intel_backlight_device_ops, &props); if (IS_ERR(bd)) { drm_err(&i915->drm, |