6.10-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
commit 5c7bb62cb8f53de71d8ab3d619be22740da0b837 upstream.
Dell All In One (AIO) models released after 2017 may use a backlight controller board connected to an UART.
In DSDT this uart port will be defined as:
Name (_HID, "DELL0501") Name (_CID, EisaId ("PNP0501")
The Dell OptiPlex 7760 AIO has an ACPI device for one if its UARTs with the above _HID + _CID. Loading the dell-uart-backlight driver shows that there actually is a backlight controller board attached to the UART, which reports a firmware version of "G&MX01-V15".
But the backlight controller board does not actually control the backlight brightness and the GPU's native backlight control method does work.
Add a quirk to use the GPU's native backlight control method on this model.
Fixes: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver") Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2303936 Cc: All applicable stable@vger.kernel.org Signed-off-by: Hans de Goede hdegoede@redhat.com Reviewed-by: Andy Shevchenko andy@kernel.org Link: https://patch.msgid.link/20240814190159.15650-4-hdegoede@redhat.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/video_detect.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
--- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -808,6 +808,21 @@ static const struct dmi_system_id video_ },
/* + * Dell AIO (All in Ones) which advertise an UART attached backlight + * controller board in their ACPI tables (and may even have one), but + * which need native backlight control nevertheless. + */ + { + /* https://bugzilla.redhat.com/show_bug.cgi?id=2303936 */ + .callback = video_detect_force_native, + /* Dell OptiPlex 7760 AIO */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7760 AIO"), + }, + }, + + /* * Models which have nvidia-ec-wmi support, but should not use it. * Note this indicates a likely firmware bug on these models and should * be revisited if/when Linux gets support for dynamic mux mode.