[PATCH AUTOSEL 5.15 60/68] drm/amd/display: update bios scratch when setting backlight

Sasha Levin
2021-11-30T14:54:36Z

From: Alex Deucher <alexander.deucher@amd.com>

[ Upstream commit 692cd92e66ee10597676530573a495dc1d3bec6a ]

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
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 96b7bb13a2dd9..12a6b1c99c93e 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 8cc0222dba191..27e74b1fc260a 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 084491afe5405..ea36f0fa59a9e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -50,6 +50,7 @@
#include <drm/drm_hdcp.h>
#endif
#include "amdgpu_pm.h"
+#include "amdgpu_atombios.h"

#include "amd_shared.h"
#include "amdgpu_dm_irq.h"
@@ -3528,6 +3529,9 @@ 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];

--
2.33.0