The backlight of the Samsung ATNA45AF01 panel used in the Qualcomm X1E80100 CRD does not work correctly with the current display panel configuration and drivers: It works after boot, but once the display gets disabled it is not possible to get it back on. It turns out that the ATNA45AF01 panel needs exactly the same non-standard power sequence as implemented for ATNA33XC20 in the panel-samsung-atna33xc20 driver. Move the ATNA45AF01 panel from the generic panel-edp driver to the panel-samsung-atna33xc20 driver and fix the panel configuration in the x1e80100-crd device tree to make the panel work correctly. The panel and DT changes can be picked up independently. Since v2 uses the existing "samsung,atna33xc20" compatible as fallback, the DT changes work even without the driver changes. Signed-off-by: Stephan Gerhold <stephan.gerhold@xxxxxxxxxx> --- Changes in v2: - Use fallback compatible to avoid changes in driver (Doug) - ... this allows applying the DT change as fix, so add Fixes: tag there - Add review tags (except Krzysztof's, since the binding changed quite a bit) - Link to v1: https://lore.kernel.org/r/20240710-x1e80100-crd-backlight-v1-0-eb242311a23e@xxxxxxxxxx --- Stephan Gerhold (4): dt-bindings: display: panel: samsung,atna33xc20: Document ATNA45AF01 Revert "drm/panel-edp: Add SDC ATNA45AF01" arm64: dts: qcom: x1e80100-crd: Fix backlight arm64: defconfig: Add CONFIG_DRM_PANEL_SAMSUNG_ATNA33XC20 .../bindings/display/panel/samsung,atna33xc20.yaml | 8 +++++++- arch/arm64/boot/dts/qcom/x1e80100-crd.dts | 17 +++++++++++++++-- arch/arm64/configs/defconfig | 1 + drivers/gpu/drm/panel/panel-edp.c | 2 -- 4 files changed, 23 insertions(+), 5 deletions(-) --- base-commit: 91e3b24eb7d297d9d99030800ed96944b8652eaf change-id: 20240710-x1e80100-crd-backlight-632f9bf936ef Best regards, -- Stephan Gerhold <stephan.gerhold@xxxxxxxxxx>
