From be0118f90e18e3fb8191f17f51a9addc93d0f185 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 23 Nov 2021 10:44:48 -0500
Subject: [PATCH] drm/amd/display: update bios scratch when setting backlight
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>
---
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 9a1ac657faa29..0747dc7922c23 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];
--
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