On 2021-11-24 11:36, Alex Deucher wrote:
> Update the bios scratch register when updating the backlight
> level. Some platforms apparently read this scratch register
> and do additional operations in their hotkey handlers.
>
> Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1518
> Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Maybe dce_driver_set_backlight should handle this but doing this
in amdgpu also works. I don't know if I have a preference either
way.
Reviewed-by: Harry Wentland <harry.wentl...@amd.com>
Harry
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 12 ++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h | 2 ++
> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++++
> 3 files changed, 18 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> index 96b7bb13a2dd..12a6b1c99c93 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> @@ -1569,6 +1569,18 @@ void amdgpu_atombios_scratch_regs_engine_hung(struct
> amdgpu_device *adev,
> WREG32(adev->bios_scratch_reg_offset + 3, tmp);
> }
>
> +void amdgpu_atombios_scratch_regs_set_backlight_level(struct amdgpu_device
> *adev,
> + u32 backlight_level)
> +{
> + u32 tmp = RREG32(adev->bios_scratch_reg_offset + 2);
> +
> + tmp &= ~ATOM_S2_CURRENT_BL_LEVEL_MASK;
> + tmp |= (backlight_level << ATOM_S2_CURRENT_BL_LEVEL_SHIFT) &
> + ATOM_S2_CURRENT_BL_LEVEL_MASK;
> +
> + WREG32(adev->bios_scratch_reg_offset + 2, tmp);
> +}
> +
> bool amdgpu_atombios_scratch_need_asic_init(struct amdgpu_device *adev)
> {
> u32 tmp = RREG32(adev->bios_scratch_reg_offset + 7);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
> index 8cc0222dba19..27e74b1fc260 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
> @@ -185,6 +185,8 @@ bool amdgpu_atombios_has_gpu_virtualization_table(struct
> amdgpu_device *adev);
> void amdgpu_atombios_scratch_regs_lock(struct amdgpu_device *adev, bool
> lock);
> void amdgpu_atombios_scratch_regs_engine_hung(struct amdgpu_device *adev,
> bool hung);
> +void amdgpu_atombios_scratch_regs_set_backlight_level(struct amdgpu_device
> *adev,
> + u32 backlight_level);
> bool amdgpu_atombios_scratch_need_asic_init(struct amdgpu_device *adev);
>
> void amdgpu_atombios_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le);
> 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 40a4269770fa..05e4a0952a2b 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -51,6 +51,7 @@
> #include <drm/drm_hdcp.h>
> #endif
> #include "amdgpu_pm.h"
> +#include "amdgpu_atombios.h"
>
> #include "amd_shared.h"
> #include "amdgpu_dm_irq.h"
> @@ -3918,6 +3919,9 @@ static int amdgpu_dm_backlight_set_level(struct
> amdgpu_display_manager *dm,
> caps = dm->backlight_caps[bl_idx];
>
> dm->brightness[bl_idx] = user_brightness;
> + /* update scratch register */
> + if (bl_idx == 0)
> + amdgpu_atombios_scratch_regs_set_backlight_level(dm->adev,
> dm->brightness[bl_idx]);
> brightness = convert_brightness_from_user(&caps,
> dm->brightness[bl_idx]);
> link = (struct dc_link *)dm->backlight_link[bl_idx];
>
>
