diff mbox

No backlight since linux-4.2.4 - drivers/gpu/drm/radeon/atombios_encoders.c

Message ID CADnq5_MPiwz0f1Zwv4iVU=XR5aT=BOpE63gb=N+Cuy8+u_cgEA@mail.gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alex Deucher Oct. 27, 2015, 4:43 p.m. UTC 
On Tue, Oct 27, 2015 at 12:23 PM, Michael Burian <michael.burian@sbg.at> wrote:
> On 10/27/15 16:10, Alex Deucher wrote:
>
>>
>> It would appear that your system does not use the gpu backlight
>> controller.  Either it's lying or messing with the GPU backlight
>> controller causes some bad interaction with whatever does control it.
>> Does the attached radeon patch help?  I'm also attaching an amdgpu
>> patch for reference in case the same problem appears on amdgpu.
>>
>
> no, still no backlight when applied against current current mainline
>
> 858e904bd71dd0057a548d6785d94ce5ec4aeabd (Merge tag 'iommu-fixes-v4.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu)
>

I see the problem.  We don't enable native backlight control on older
asics like yours by default.  Does the attached patch help?

Alex

Comments

Michael Burian Oct. 27, 2015, 5:02 p.m. UTC | #1 
On 10/27/15 17:43, Alex Deucher wrote:
> 
> I see the problem.  We don't enable native backlight control on older
> asics like yours by default.  Does the attached patch help?
> 

Yes, backlight is on again. (tested against mainline: 858e904bd71dd0057a548d6785d94ce5ec4aeabd)

thanks
Michel Dänzer Oct. 28, 2015, 7:11 a.m. UTC | #2 
On 28.10.2015 01:43, Alex Deucher wrote:
> On Tue, Oct 27, 2015 at 12:23 PM, Michael Burian <michael.burian@sbg.at> wrote:
>> On 10/27/15 16:10, Alex Deucher wrote:
>>
>>>
>>> It would appear that your system does not use the gpu backlight
>>> controller.  Either it's lying or messing with the GPU backlight
>>> controller causes some bad interaction with whatever does control it.
>>> Does the attached radeon patch help?  I'm also attaching an amdgpu
>>> patch for reference in case the same problem appears on amdgpu.
>>>
>>
>> no, still no backlight when applied against current current mainline
>>
>> 858e904bd71dd0057a548d6785d94ce5ec4aeabd (Merge tag 'iommu-fixes-v4.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu)
>>
> 
> I see the problem.  We don't enable native backlight control on older
> asics like yours by default.  Does the attached patch help?

My only doubt about this patch is: Should we also fall back to the old
beahviour in the !(rdev->mode_info.firmware_flags &
ATOM_BIOS_INFO_BL_CONTROLLED_BY_GPU) case?
diff mbox

Patch

From 8940e9553ae9097a22c2c46a0d33a6ce7fd6d9b2 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 27 Oct 2015 10:56:44 -0400
Subject: [PATCH] drm/radeon: fix dpms when driver backlight control is
 disabled

If driver backlight control is disabled, either by driver
parameter or default per-asic setting, revert to the old behavior.

Fixes a regression in commit:
4281f46ef839050d2ef60348f661eb463c21cc2e

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/radeon/atombios_encoders.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 65adb9c..ec0f5f6 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1624,9 +1624,14 @@  radeon_atom_encoder_dpms_avivo(struct drm_encoder *encoder, int mode)
 		} else
 			atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
-			struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
+			if (rdev->mode_info.bl_encoder) {
+				struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
 
-			atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+				atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+			} else {
+				args.ucAction = ATOM_LCD_BLON;
+				atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
+			}
 		}
 		break;
 	case DRM_MODE_DPMS_STANDBY:
@@ -1706,8 +1711,13 @@  radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 			if (ASIC_IS_DCE4(rdev))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
-		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT))
-			atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
+			if (rdev->mode_info.bl_encoder)
+				atombios_set_backlight_level(radeon_encoder, dig->backlight_level);
+			else
+				atombios_dig_transmitter_setup(encoder,
+							       ATOM_TRANSMITTER_ACTION_LCD_BLON, 0, 0);
+		}
 		if (ext_encoder)
 			atombios_external_encoder_setup(encoder, ext_encoder, ATOM_ENABLE);
 		break;
-- 
1.8.3.1