[PATCH] The Apple iMac11, 1 (late 2009) has an integrated ATI Mobility Radeon HD 4850. This machine suffers from a similar problem as the iMac10, 1 (late 2009) and the iMac11, 2 (mid 2010). This small patch fixes the issue on this machine.

[PATCH] The Apple iMac11, 1 (late 2009) has an integrated ATI Mobility Radeon HD 4850. This machine suffers from a similar problem as the iMac10, 1 (late 2009) and the iMac11, 2 (mid 2010). This small patch fixes the issue on this machine.

[Gilles Risch]

Fixes freedesktop issue 164
Link: https://gitlab.freedesktop.org/xorg/driver/xf86-video-ati/-/issues/164
---
 drivers/gpu/drm/radeon/atombios_crtc.c     | 4 ++--
 drivers/gpu/drm/radeon/atombios_encoders.c | 9 +++++----
 drivers/gpu/drm/radeon/radeon.h            | 1 +
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0..3c6d33273 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -580,7 +580,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 			radeon_crtc->pll_flags |= (/*RADEON_PLL_USE_FRAC_FB_DIV |*/
 				RADEON_PLL_PREFER_CLOSEST_LOWER);
 
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 200000)	/* range limits??? */
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 200000)	/* range limits??? */
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
 		else
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
@@ -594,7 +594,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 5cfd8fcfa..4e984973c 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
+	 * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
+	 * so there use linkb, otherwise the internal eDP panel will stay dark.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
+	if (ASIC_IS_DCE31(rdev)) {
 		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+		    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
 		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
 			enc_idx = (dig->linkb) ? 1 : 0;
 		else
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 527b9d19d..6b7c0abe4 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
 			    (rdev->family == CHIP_RS740)  ||	\
 			    (rdev->family >= CHIP_R600))
 #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
+#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
 #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
 #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
 #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
-- 
2.47.3

[PATCH v2] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

The Apple iMac11,1 (late 2009) has an integrated ATI Mobility Radeon
HD 4850 (RV770/M98L) with a 2560x1440 internal panel connected via an
internal DisplayPort path. This machine suffers from a similar problem
as the iMac10,1 (late 2009) and the iMac11,2 (mid 2010). Without this
fix the display stays dark under KMS. Two issues are addressed:

1. The RV770 implements DCE3.1 and not DCE3.2. ASIC_IS_DCE32() starts at
   CHIP_RV730 which is newer than RV770, so the RV770 never matched the
   DCE3.2 PLL and encoder logic. Introduce ASIC_IS_DCE31() starting at
   CHIP_RV770 to fix this.

2. Apple routed the internal display through Link B of the DIG encoder
   instead of Link A, as observed in the kernel display connector log.
   The same quirk already exists for iMac10,1 and iMac11,2 - iMac11,1
   was simply missing from the list.

Note: resume from suspend still results in a dark screen as the DP
re-driver chips on the mainboard lose their state during power-off.
This will be addressed in a follow-up patch.

Fixes freedesktop issue 164
Link: https://gitlab.freedesktop.org/xorg/driver/xf86-video-ati/-/issues/164

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
v2: No code changes. Fixed commit message:
    - Added drm/radeon: prefix to subject line
    - Added empty line between subject and body
    - Added technical description of the changes

 drivers/gpu/drm/radeon/atombios_crtc.c     | 4 ++--
 drivers/gpu/drm/radeon/atombios_encoders.c | 9 +++++----
 drivers/gpu/drm/radeon/radeon.h            | 1 +
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0d6c..3c6d332739e3 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -580,7 +580,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 			radeon_crtc->pll_flags |= (/*RADEON_PLL_USE_FRAC_FB_DIV |*/
 				RADEON_PLL_PREFER_CLOSEST_LOWER);
 
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 200000)	/* range limits??? */
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 200000)	/* range limits??? */
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
 		else
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
@@ -594,7 +594,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 5cfd8fcfa5e8..4e984973c043 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
+	 * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
+	 * so there use linkb, otherwise the internal eDP panel will stay dark.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
+	if (ASIC_IS_DCE31(rdev)) {
 		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+		    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
 		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
 			enc_idx = (dig->linkb) ? 1 : 0;
 		else
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 527b9d19d730..6b7c0abe49fb 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
 			    (rdev->family == CHIP_RS740)  ||	\
 			    (rdev->family >= CHIP_R600))
 #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
+#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
 #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
 #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
 #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
-- 
2.47.3

Re: [PATCH v2] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Lukas Wunner]

On Sat, May 16, 2026 at 11:24:21AM +0200, Gilles Risch wrote:
> The Apple iMac11,1 (late 2009) has an integrated ATI Mobility Radeon
> HD 4850 (RV770/M98L) with a 2560x1440 internal panel connected via an
> internal DisplayPort path. This machine suffers from a similar problem
> as the iMac10,1 (late 2009) and the iMac11,2 (mid 2010). Without this
> fix the display stays dark under KMS. Two issues are addressed:
> 
> 1. The RV770 implements DCE3.1 and not DCE3.2. ASIC_IS_DCE32() starts at
>    CHIP_RV730 which is newer than RV770, so the RV770 never matched the
>    DCE3.2 PLL and encoder logic. Introduce ASIC_IS_DCE31() starting at
>    CHIP_RV770 to fix this.
> 
> 2. Apple routed the internal display through Link B of the DIG encoder
>    instead of Link A, as observed in the kernel display connector log.
>    The same quirk already exists for iMac10,1 and iMac11,2 - iMac11,1
>    was simply missing from the list.

Not an expert in the radeon driver or AMD chip revisions, but if it
helps improve support for older Macs I'll be happy to offer my:

Reviewed-by: Lukas Wunner <lukas@wunner.de>

It's not immediately obvious that CHIP_RV770 precedes CHIP_RV730
in the enum and that hence ASIC_IS_DCE31() subsumes ASIC_IS_DCE32().

Thanks,

Lukas

[PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Gilles Risch]

After suspend/resume the internal eDP display on iMac11,1 (and
potentially other DCE3.1 systems) stays dark because
atombios_set_edp_panel_power() skips panel power control for
anything older than DCE4.

Fix this by:
- Extending atombios_set_edp_panel_power() to also handle DCE3.1
  by changing the !ASIC_IS_DCE4() guard to !ASIC_IS_DCE31().
  HPD polling works correctly on DCE3.1 (verified: HPD is asserted
  at iteration 0 on iMac11,1).
- Issuing ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF for DCE3.1 in addition
  to DCE4+.

Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
 drivers/gpu/drm/radeon/atombios_encoders.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 4e984973c043..b62fd713efcf 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1383,7 +1383,7 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
 	if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
 		goto done;
 
-	if (!ASIC_IS_DCE4(rdev))
+	if (!ASIC_IS_DCE31(rdev))
 		goto done;
 
 	if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
@@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
 			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
 			radeon_dp_link_train(encoder, connector);
-			if (ASIC_IS_DCE4(rdev))
+			if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
@@ -1724,7 +1724,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 	case DRM_MODE_DPMS_SUSPEND:
 	case DRM_MODE_DPMS_OFF:
 
-		if (ASIC_IS_DCE4(rdev)) {
+		if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev)) {
 			if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
 		}
-- 
2.47.3

Re: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[kernel test robot]

Hi Gilles,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on linus/master v7.1-rc3 next-20260508]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gilles-Risch/drm-radeon-fix-eDP-resume-from-suspend-on-iMac11-1-DCE3-1-systems/20260517-025343
base:   https://gitlab.freedesktop.org/drm/misc/kernel.git drm-misc-next
patch link:    https://lore.kernel.org/r/20260516185226.3005-1-gilles.risch%40gmail.com
patch subject: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems
config: riscv-randconfig-001-20260517 (https://download.01.org/0day-ci/archive/20260517/202605171126.1g7CRkTZ-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 5bac06718f502014fade905512f1d26d578a18f3)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260517/202605171126.1g7CRkTZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605171126.1g7CRkTZ-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/radeon/atombios_encoders.c:1386:7: error: call to undeclared function 'ASIC_IS_DCE31'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1386 |         if (!ASIC_IS_DCE31(rdev))
         |              ^
   drivers/gpu/drm/radeon/atombios_encoders.c:1710:30: error: call to undeclared function 'ASIC_IS_DCE31'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1710 |                         if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev))
         |                                                   ^
   drivers/gpu/drm/radeon/atombios_encoders.c:1727:29: error: call to undeclared function 'ASIC_IS_DCE31'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1727 |                 if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev)) {
         |                                           ^
   3 errors generated.


vim +/ASIC_IS_DCE31 +1386 drivers/gpu/drm/radeon/atombios_encoders.c

  1372	
  1373	bool
  1374	atombios_set_edp_panel_power(struct drm_connector *connector, int action)
  1375	{
  1376		struct radeon_connector *radeon_connector = to_radeon_connector(connector);
  1377		struct drm_device *dev = radeon_connector->base.dev;
  1378		struct radeon_device *rdev = dev->dev_private;
  1379		union dig_transmitter_control args;
  1380		int index = GetIndexIntoMasterTable(COMMAND, UNIPHYTransmitterControl);
  1381		uint8_t frev, crev;
  1382	
  1383		if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
  1384			goto done;
  1385	
> 1386		if (!ASIC_IS_DCE31(rdev))
  1387			goto done;
  1388	
  1389		if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
  1390		    (action != ATOM_TRANSMITTER_ACTION_POWER_OFF))
  1391			goto done;
  1392	
  1393		if (!atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev))
  1394			goto done;
  1395	
  1396		memset(&args, 0, sizeof(args));
  1397	
  1398		args.v1.ucAction = action;
  1399	
  1400		atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args, sizeof(args));
  1401	
  1402		/* wait for the panel to power up */
  1403		if (action == ATOM_TRANSMITTER_ACTION_POWER_ON) {
  1404			int i;
  1405	
  1406			for (i = 0; i < 300; i++) {
  1407				if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd))
  1408					return true;
  1409				mdelay(1);
  1410			}
  1411			return false;
  1412		}
  1413	done:
  1414		return true;
  1415	}
  1416	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[kernel test robot]

Hi Gilles,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on linus/master v7.1-rc3 next-20260508]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gilles-Risch/drm-radeon-fix-eDP-resume-from-suspend-on-iMac11-1-DCE3-1-systems/20260517-025343
base:   https://gitlab.freedesktop.org/drm/misc/kernel.git drm-misc-next
patch link:    https://lore.kernel.org/r/20260516185226.3005-1-gilles.risch%40gmail.com
patch subject: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems
config: riscv-randconfig-002-20260517 (https://download.01.org/0day-ci/archive/20260517/202605171301.73YzX9wA-lkp@intel.com/config)
compiler: riscv32-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260517/202605171301.73YzX9wA-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605171301.73YzX9wA-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/gpu/drm/radeon/atombios_encoders.c: In function 'atombios_set_edp_panel_power':
>> drivers/gpu/drm/radeon/atombios_encoders.c:1386:14: error: implicit declaration of function 'ASIC_IS_DCE31'; did you mean 'ASIC_IS_DCE3'? [-Wimplicit-function-declaration]
    1386 |         if (!ASIC_IS_DCE31(rdev))
         |              ^~~~~~~~~~~~~
         |              ASIC_IS_DCE3


vim +1386 drivers/gpu/drm/radeon/atombios_encoders.c

  1372	
  1373	bool
  1374	atombios_set_edp_panel_power(struct drm_connector *connector, int action)
  1375	{
  1376		struct radeon_connector *radeon_connector = to_radeon_connector(connector);
  1377		struct drm_device *dev = radeon_connector->base.dev;
  1378		struct radeon_device *rdev = dev->dev_private;
  1379		union dig_transmitter_control args;
  1380		int index = GetIndexIntoMasterTable(COMMAND, UNIPHYTransmitterControl);
  1381		uint8_t frev, crev;
  1382	
  1383		if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
  1384			goto done;
  1385	
> 1386		if (!ASIC_IS_DCE31(rdev))
  1387			goto done;
  1388	
  1389		if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
  1390		    (action != ATOM_TRANSMITTER_ACTION_POWER_OFF))
  1391			goto done;
  1392	
  1393		if (!atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev))
  1394			goto done;
  1395	
  1396		memset(&args, 0, sizeof(args));
  1397	
  1398		args.v1.ucAction = action;
  1399	
  1400		atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args, sizeof(args));
  1401	
  1402		/* wait for the panel to power up */
  1403		if (action == ATOM_TRANSMITTER_ACTION_POWER_ON) {
  1404			int i;
  1405	
  1406			for (i = 0; i < 300; i++) {
  1407				if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd))
  1408					return true;
  1409				mdelay(1);
  1410			}
  1411			return false;
  1412		}
  1413	done:
  1414		return true;
  1415	}
  1416	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v2] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

Good afternoon Lukas,

thanks for the review.

The initial launch date can either be verified in the TeraScale 
architecture comparison table on Wikipedia [1] or directly in the kernel 
source at drivers/gpu/drm/radeon/radeon_family.h where CHIP_RV770 (line 
74) precedes CHIP_RV730 (line 75).

The test robot mentions that it cannot find ASIC_IS_DCE31(); this is 
because both patches build on one another. Should I submit both patches 
as a series?

Kind regards,
Gilles

On 16.05.26 20:09, Lukas Wunner wrote:
> On Sat, May 16, 2026 at 11:24:21AM +0200, Gilles Risch wrote:
>> The Apple iMac11,1 (late 2009) has an integrated ATI Mobility Radeon
>> HD 4850 (RV770/M98L) with a 2560x1440 internal panel connected via an
>> internal DisplayPort path. This machine suffers from a similar problem
>> as the iMac10,1 (late 2009) and the iMac11,2 (mid 2010). Without this
>> fix the display stays dark under KMS. Two issues are addressed:
>>
>> 1. The RV770 implements DCE3.1 and not DCE3.2. ASIC_IS_DCE32() starts at
>>     CHIP_RV730 which is newer than RV770, so the RV770 never matched the
>>     DCE3.2 PLL and encoder logic. Introduce ASIC_IS_DCE31() starting at
>>     CHIP_RV770 to fix this.
>>
>> 2. Apple routed the internal display through Link B of the DIG encoder
>>     instead of Link A, as observed in the kernel display connector log.
>>     The same quirk already exists for iMac10,1 and iMac11,2 - iMac11,1
>>     was simply missing from the list.
> Not an expert in the radeon driver or AMD chip revisions, but if it
> helps improve support for older Macs I'll be happy to offer my:
>
> Reviewed-by: Lukas Wunner <lukas@wunner.de>
>
> It's not immediately obvious that CHIP_RV770 precedes CHIP_RV730
> in the enum and that hence ASIC_IS_DCE31() subsumes ASIC_IS_DCE32().
>
> Thanks,
>
> Lukas

Re: [PATCH v2] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Lukas Wunner]

On Sun, May 17, 2026 at 03:53:51PM +0200, Gilles Risch wrote:
> The test robot mentions that it cannot find ASIC_IS_DCE31(); this is because
> both patches build on one another. Should I submit both patches as a series?

Yes, either that or wait for the first patch to be applied and show up in
the drm-next repo.  Then 0-day should not complain.

Usually people are annoyed if patches are resubmitted in short cadence,
so the polite thing to do is wait for 1 or 2 weeks before respinning
so that people get a chance to provide further comments.

Thanks,

Lukas

Re: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Alex Deucher]

[-- Attachment #1: Type: text/plain, Size: 2843 bytes --]

On Sat, May 16, 2026 at 2:52 PM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> After suspend/resume the internal eDP display on iMac11,1 (and
> potentially other DCE3.1 systems) stays dark because
> atombios_set_edp_panel_power() skips panel power control for
> anything older than DCE4.
>
> Fix this by:
> - Extending atombios_set_edp_panel_power() to also handle DCE3.1
>   by changing the !ASIC_IS_DCE4() guard to !ASIC_IS_DCE31().
>   HPD polling works correctly on DCE3.1 (verified: HPD is asserted
>   at iteration 0 on iMac11,1).
> - Issuing ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF for DCE3.1 in addition
>   to DCE4+.
>
> Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).
>
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> ---
>  drivers/gpu/drm/radeon/atombios_encoders.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> index 4e984973c043..b62fd713efcf 100644
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> @@ -1383,7 +1383,7 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
>         if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
>                 goto done;
>
> -       if (!ASIC_IS_DCE4(rdev))
> +       if (!ASIC_IS_DCE31(rdev))
>                 goto done;
>
>         if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
> @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>                         radeon_dp_link_train(encoder, connector);
> -                       if (ASIC_IS_DCE4(rdev))
> +                       if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev))
>                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>                 }
>                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> @@ -1724,7 +1724,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>         case DRM_MODE_DPMS_SUSPEND:
>         case DRM_MODE_DPMS_OFF:
>
> -               if (ASIC_IS_DCE4(rdev)) {
> +               if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev)) {
>                         if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
>                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
>                 }

These changes don't make sense and will break other DCE3.c boards.   I
had the attached patch from you in one of my old branches, does it fix
the issue?

Alex

[-- Attachment #2: 0001-drm-radeon-Fix-eDP-for-single-display-iMac11-1.patch --]
[-- Type: text/x-patch, Size: 3753 bytes --]

From ca4fc2fd58dcd3bf9f6afd8d37b27a1cfcc42337 Mon Sep 17 00:00:00 2001
From: Gilles Risch <gilles.risch@gmail.com>
Date: Fri, 17 Nov 2023 20:48:24 +0100
Subject: [PATCH] drm/radeon: Fix eDP for single-display iMac11,1

The Apple iMac11,1 (late 2009) has an integrated ATI Mobility Radeon HD 4850.
This machine suffers from a similar problem as the iMac10,1 (late 2009) and
the iMac11,2 (mid 2010). This small patch fixes the issue on this machine.

Fixes freedesktop issue 164
Link: https://gitlab.freedesktop.org/xorg/driver/xf86-video-ati/-/issues/164

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/atombios_crtc.c     | 4 ++--
 drivers/gpu/drm/radeon/atombios_encoders.c | 9 +++++----
 drivers/gpu/drm/radeon/radeon.h            | 1 +
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0d6c5..3c6d332739e3c 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -580,7 +580,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 			radeon_crtc->pll_flags |= (/*RADEON_PLL_USE_FRAC_FB_DIV |*/
 				RADEON_PLL_PREFER_CLOSEST_LOWER);
 
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 200000)	/* range limits??? */
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 200000)	/* range limits??? */
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
 		else
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
@@ -594,7 +594,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 3d9f47bc807af..37da7961ce792 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
+	 * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
+	 * so there use linkb, otherwise the internal eDP panel will stay dark.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
+	if (ASIC_IS_DCE31(rdev)) {
 		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+		    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
 		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
 			enc_idx = (dig->linkb) ? 1 : 0;
 		else
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 527b9d19d7306..6b7c0abe49fb7 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
 			    (rdev->family == CHIP_RS740)  ||	\
 			    (rdev->family >= CHIP_R600))
 #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
+#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
 #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
 #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
 #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
-- 
2.54.0

Re: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Gilles Risch]

Am Mo., 18. Mai 2026 um 16:13 Uhr schrieb Alex Deucher <alexdeucher@gmail.com>:
>
> On Sat, May 16, 2026 at 2:52 PM Gilles Risch <gilles.risch@gmail.com> wrote:
> >
> > After suspend/resume the internal eDP display on iMac11,1 (and
> > potentially other DCE3.1 systems) stays dark because
> > atombios_set_edp_panel_power() skips panel power control for
> > anything older than DCE4.
> >
> > Fix this by:
> > - Extending atombios_set_edp_panel_power() to also handle DCE3.1
> >   by changing the !ASIC_IS_DCE4() guard to !ASIC_IS_DCE31().
> >   HPD polling works correctly on DCE3.1 (verified: HPD is asserted
> >   at iteration 0 on iMac11,1).
> > - Issuing ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF for DCE3.1 in addition
> >   to DCE4+.
> >
> > Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).
> >
> > Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> > ---
> >  drivers/gpu/drm/radeon/atombios_encoders.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> > index 4e984973c043..b62fd713efcf 100644
> > --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> > +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> > @@ -1383,7 +1383,7 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
> >         if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
> >                 goto done;
> >
> > -       if (!ASIC_IS_DCE4(rdev))
> > +       if (!ASIC_IS_DCE31(rdev))
> >                 goto done;
> >
> >         if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
> > @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
> >                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
> >                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
> >                         radeon_dp_link_train(encoder, connector);
> > -                       if (ASIC_IS_DCE4(rdev))
> > +                       if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev))
> >                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
> >                 }
> >                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> > @@ -1724,7 +1724,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
> >         case DRM_MODE_DPMS_SUSPEND:
> >         case DRM_MODE_DPMS_OFF:
> >
> > -               if (ASIC_IS_DCE4(rdev)) {
> > +               if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev)) {
> >                         if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
> >                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
> >                 }
>
> These changes don't make sense and will break other DCE3.c boards.   I
> had the attached patch from you in one of my old branches, does it fix
> the issue?
>
> Alex

While the initial attached patch resolved the dark screen issue after
a fresh boot, this follow-up patch addresses the same problem
occurring after resuming from suspend. Should I used dmi_match() to
avoid breaking other DCE3.c boards?

Regards,
Gilles

Re: [PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Alex Deucher]

On Mon, May 18, 2026 at 10:40 AM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> Am Mo., 18. Mai 2026 um 16:13 Uhr schrieb Alex Deucher <alexdeucher@gmail.com>:
> >
> > On Sat, May 16, 2026 at 2:52 PM Gilles Risch <gilles.risch@gmail.com> wrote:
> > >
> > > After suspend/resume the internal eDP display on iMac11,1 (and
> > > potentially other DCE3.1 systems) stays dark because
> > > atombios_set_edp_panel_power() skips panel power control for
> > > anything older than DCE4.
> > >
> > > Fix this by:
> > > - Extending atombios_set_edp_panel_power() to also handle DCE3.1
> > >   by changing the !ASIC_IS_DCE4() guard to !ASIC_IS_DCE31().
> > >   HPD polling works correctly on DCE3.1 (verified: HPD is asserted
> > >   at iteration 0 on iMac11,1).
> > > - Issuing ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF for DCE3.1 in addition
> > >   to DCE4+.
> > >
> > > Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).
> > >
> > > Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> > > ---
> > >  drivers/gpu/drm/radeon/atombios_encoders.c | 6 +++---
> > >  1 file changed, 3 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> > > index 4e984973c043..b62fd713efcf 100644
> > > --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> > > +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> > > @@ -1383,7 +1383,7 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
> > >         if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
> > >                 goto done;
> > >
> > > -       if (!ASIC_IS_DCE4(rdev))
> > > +       if (!ASIC_IS_DCE31(rdev))
> > >                 goto done;
> > >
> > >         if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
> > > @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
> > >                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
> > >                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
> > >                         radeon_dp_link_train(encoder, connector);
> > > -                       if (ASIC_IS_DCE4(rdev))
> > > +                       if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev))
> > >                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
> > >                 }
> > >                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> > > @@ -1724,7 +1724,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
> > >         case DRM_MODE_DPMS_SUSPEND:
> > >         case DRM_MODE_DPMS_OFF:
> > >
> > > -               if (ASIC_IS_DCE4(rdev)) {
> > > +               if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev)) {
> > >                         if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
> > >                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
> > >                 }
> >
> > These changes don't make sense and will break other DCE3.c boards.   I
> > had the attached patch from you in one of my old branches, does it fix
> > the issue?
> >
> > Alex
>
> While the initial attached patch resolved the dark screen issue after
> a fresh boot, this follow-up patch addresses the same problem
> occurring after resuming from suspend. Should I used dmi_match() to
> avoid breaking other DCE3.c boards?

Yes.  Even that is a hack.  You are effectively just skipping some of
the required programming sequences.  Presumably the mac is wired up
strangely or there are issues with its atom tables.  Ideally we'd sort
that out, but this hardware is pretty old so I'm ok with a hack.

Alex

[PATCH v3 0/2] drm/radeon: fix iMac11,1 dark display

[Gilles Risch]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1481 bytes --]

Hello Alex,

thank you for the feedback. I've updated the patch to use dmi_match()
as suggested, limited to iMac11,1 only since that is the only machine
I have tested so far.

I will have access to other older Apple iMacs which also show display
issues under Linux. Given your comment about unusual wiring and
potentially broken atom tables on these machines, it would make sense
to investigate this more thoroughly in the long run. I would be happy
to help with testing if that would be useful.

The build error reported by the kernel test robot is also fixed — the
previous version was missing the dependency on the ASIC_IS_DCE31()
macro introduced in patch 1. Both patches are now submitted together
as a series.

Changes in v3:
- Submit both patches together as a series to fix the build dependency
- Use dmi_match(DMI_PRODUCT_NAME, "iMac11,1") instead of
  ASIC_IS_DCE31() to avoid breaking other DCE3.x boards
  (suggested by Alex Deucher)
- Limit fix to iMac11,1 only (only tested machine)

Tested on iMac11,1 with Debian Linux.

Gilles Risch (2):
  drm/radeon: fix internal display on iMac11,1 (RV770/DCE3.1)
  drm/radeon: fix eDP resume from suspend on iMac11,1 / DCE3.1 systems

 drivers/gpu/drm/radeon/atombios_crtc.c     |  4 ++--
 drivers/gpu/drm/radeon/atombios_encoders.c | 16 +++++++++-------
 drivers/gpu/drm/radeon/radeon.h            |  1 +
 3 files changed, 12 insertions(+), 9 deletions(-)


base-commit: 6916d5703ddf9a38f1f6c2cc793381a24ee914c6
-- 
2.47.3

[PATCH v3 1/2] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

The Apple iMac11,1 (late 2009) has an integrated ATI Mobility Radeon
HD 4850 (RV770/M98L) with a 2560x1440 internal panel connected via an
internal DisplayPort path. This machine suffers from a similar problem
as the iMac10,1 (late 2009) and the iMac11,2 (mid 2010). Without this
fix the display stays dark under KMS. Two issues are addressed:

1. The RV770 implements DCE3.1 and not DCE3.2. ASIC_IS_DCE32() starts at
   CHIP_RV730 which is newer than RV770, so the RV770 never matched the
   DCE3.2 PLL and encoder logic. Introduce ASIC_IS_DCE31() starting at
   CHIP_RV770 to fix this.

2. Apple routed the internal display through Link B of the DIG encoder
   instead of Link A, as observed in the kernel display connector log.
   The same quirk already exists for iMac10,1 and iMac11,2 - iMac11,1
   was simply missing from the list.

Note: resume from suspend still results in a dark screen as the DP
re-driver chips on the mainboard lose their state during power-off.
This will be addressed in a follow-up patch.

Fixes freedesktop issue 164
Link: https://gitlab.freedesktop.org/xorg/driver/xf86-video-ati/-/issues/164

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
v3: No code changes. 

 drivers/gpu/drm/radeon/atombios_crtc.c     | 4 ++--
 drivers/gpu/drm/radeon/atombios_encoders.c | 9 +++++----
 drivers/gpu/drm/radeon/radeon.h            | 1 +
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0d6c..3c6d332739e3 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -580,7 +580,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 			radeon_crtc->pll_flags |= (/*RADEON_PLL_USE_FRAC_FB_DIV |*/
 				RADEON_PLL_PREFER_CLOSEST_LOWER);
 
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 200000)	/* range limits??? */
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 200000)	/* range limits??? */
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
 		else
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
@@ -594,7 +594,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if (ASIC_IS_DCE31(rdev) && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 5cfd8fcfa5e8..4e984973c043 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
+	 * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
+	 * so there use linkb, otherwise the internal eDP panel will stay dark.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
+	if (ASIC_IS_DCE31(rdev)) {
 		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+		    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
 		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
 			enc_idx = (dig->linkb) ? 1 : 0;
 		else
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 527b9d19d730..6b7c0abe49fb 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
 			    (rdev->family == CHIP_RS740)  ||	\
 			    (rdev->family >= CHIP_R600))
 #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
+#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
 #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
 #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
 #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
-- 
2.47.3

[PATCH v3 2/2] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Gilles Risch]

After suspend/resume the internal eDP display on Apple iMac11,1,
stays dark because atombios_set_edp_panel_power() skips panel
power control for anything older than DCE4, and
ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF is required on ths iMac.

Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
 drivers/gpu/drm/radeon/atombios_encoders.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 4e984973c043..0a699a887ee9 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1384,7 +1384,8 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
 		goto done;
 
 	if (!ASIC_IS_DCE4(rdev))
-		goto done;
+	    if (!dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
+		    goto done;
 
 	if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
 	    (action != ATOM_TRANSMITTER_ACTION_POWER_OFF))
@@ -1707,7 +1708,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
 			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
 			radeon_dp_link_train(encoder, connector);
-			if (ASIC_IS_DCE4(rdev))
+			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
@@ -1724,7 +1725,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 	case DRM_MODE_DPMS_SUSPEND:
 	case DRM_MODE_DPMS_OFF:
 
-		if (ASIC_IS_DCE4(rdev)) {
+		if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1")) {
 			if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
 		}
-- 
2.47.3

Re: [PATCH v3 1/2] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Alex Deucher]

On Tue, May 19, 2026 at 3:19 AM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> The Apple iMac11,1 (late 2009) has an integrated ATI Mobility Radeon
> HD 4850 (RV770/M98L) with a 2560x1440 internal panel connected via an
> internal DisplayPort path. This machine suffers from a similar problem
> as the iMac10,1 (late 2009) and the iMac11,2 (mid 2010). Without this
> fix the display stays dark under KMS. Two issues are addressed:
>
> 1. The RV770 implements DCE3.1 and not DCE3.2. ASIC_IS_DCE32() starts at
>    CHIP_RV730 which is newer than RV770, so the RV770 never matched the
>    DCE3.2 PLL and encoder logic. Introduce ASIC_IS_DCE31() starting at
>    CHIP_RV770 to fix this.
>
> 2. Apple routed the internal display through Link B of the DIG encoder
>    instead of Link A, as observed in the kernel display connector log.
>    The same quirk already exists for iMac10,1 and iMac11,2 - iMac11,1
>    was simply missing from the list.
>
> Note: resume from suspend still results in a dark screen as the DP
> re-driver chips on the mainboard lose their state during power-off.
> This will be addressed in a follow-up patch.
>
> Fixes freedesktop issue 164
> Link: https://gitlab.freedesktop.org/xorg/driver/xf86-video-ati/-/issues/164
>
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> ---
> v3: No code changes.
>
>  drivers/gpu/drm/radeon/atombios_crtc.c     | 4 ++--
>  drivers/gpu/drm/radeon/atombios_encoders.c | 9 +++++----
>  drivers/gpu/drm/radeon/radeon.h            | 1 +
>  3 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 2fc0334e0d6c..3c6d332739e3 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -580,7 +580,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>                         radeon_crtc->pll_flags |= (/*RADEON_PLL_USE_FRAC_FB_DIV |*/
>                                 RADEON_PLL_PREFER_CLOSEST_LOWER);
>
> -               if (ASIC_IS_DCE32(rdev) && mode->clock > 200000)        /* range limits??? */
> +               if (ASIC_IS_DCE31(rdev) && mode->clock > 200000)        /* range limits??? */
>                         radeon_crtc->pll_flags |= RADEON_PLL_PREFER_HIGH_FB_DIV;
>                 else
>                         radeon_crtc->pll_flags |= RADEON_PLL_PREFER_LOW_REF_DIV;
> @@ -594,7 +594,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>                 if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
>                     && !radeon_crtc->ss_enabled)
>                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> -               if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
> +               if (ASIC_IS_DCE31(rdev) && mode->clock > 165000)

Can you switch these to dmi matches as well?  This change will also
change the behavior for other boards with respect to the PLL
calculations which are often pretty sensitive and may cause
regressions.

Alex

>                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
>         } else {
>                 radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> index 5cfd8fcfa5e8..4e984973c043 100644
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> @@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
>         }
>
>         /*
> -        * On DCE32 any encoder can drive any block so usually just use crtc id,
> -        * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
> -        * otherwise the internal eDP panel will stay dark.
> +        * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
> +        * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
> +        * so there use linkb, otherwise the internal eDP panel will stay dark.
>          */
> -       if (ASIC_IS_DCE32(rdev)) {
> +       if (ASIC_IS_DCE31(rdev)) {
>                 if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> +                   dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
>                     dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
>                         enc_idx = (dig->linkb) ? 1 : 0;
>                 else
> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> index 527b9d19d730..6b7c0abe49fb 100644
> --- a/drivers/gpu/drm/radeon/radeon.h
> +++ b/drivers/gpu/drm/radeon/radeon.h
> @@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
>                             (rdev->family == CHIP_RS740)  ||    \
>                             (rdev->family >= CHIP_R600))
>  #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
> +#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
>  #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
>  #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
>  #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
> --
> 2.47.3
>

Re: [PATCH v3 2/2] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Alex Deucher]

On Tue, May 19, 2026 at 3:44 AM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> After suspend/resume the internal eDP display on Apple iMac11,1,
> stays dark because atombios_set_edp_panel_power() skips panel
> power control for anything older than DCE4, and
> ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF is required on ths iMac.
>
> Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).
>
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> ---
>  drivers/gpu/drm/radeon/atombios_encoders.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> index 4e984973c043..0a699a887ee9 100644
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> @@ -1384,7 +1384,8 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
>                 goto done;
>
>         if (!ASIC_IS_DCE4(rdev))
> -               goto done;
> +           if (!dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> +                   goto done;

This logic is harder to follow.  I would just add an additional check.  E.g.,

         if (!ASIC_IS_DCE4(rdev))
               goto done;

          if (!dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
                  goto done;

Other than that, looks good to me.

>
>         if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
>             (action != ATOM_TRANSMITTER_ACTION_POWER_OFF))
> @@ -1707,7 +1708,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>                         radeon_dp_link_train(encoder, connector);
> -                       if (ASIC_IS_DCE4(rdev))
> +                       if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
>                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>                 }
>                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> @@ -1724,7 +1725,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>         case DRM_MODE_DPMS_SUSPEND:
>         case DRM_MODE_DPMS_OFF:
>
> -               if (ASIC_IS_DCE4(rdev)) {
> +               if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1")) {
>                         if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
>                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
>                 }
> --
> 2.47.3
>

[PATCH v4] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
(RV770/DCE3.1) with a 2560x1440 internal panel on an internal
DisplayPort path. Without this fix the display stays dark under KMS.

The same problem already exists for iMac10,1 and iMac11,2. Three fixes:

1. Introduce ASIC_IS_DCE31() for CHIP_RV770 and newer. Note that
   CHIP_RV770 precedes CHIP_RV730 in the enum, so ASIC_IS_DCE31()
   subsumes ASIC_IS_DCE32().

2. Extend the Link B encoder quirk from ASIC_IS_DCE32() to
   ASIC_IS_DCE31() and add iMac11,1 to the DMI list.

3. The 2560x1440 panel needs RADEON_PLL_USE_FRAC_FB_DIV and
   ATOM_ENCODER_CMD_DP_VIDEO_ON. These are limited to iMac11,1
   via dmi_match() to avoid affecting other DCE3.1 boards.

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
 drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
 drivers/gpu/drm/radeon/atombios_encoders.c | 11 ++++++-----
 drivers/gpu/drm/radeon/radeon.h            |  1 +
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0..075eba2d4 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -24,6 +24,8 @@
  *          Alex Deucher
  */
 
+#include <linux/dmi.h>
+
 #include <drm/drm_fixed.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
@@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
+		    && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 5cfd8fcfa..4de60559f 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
 			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
 			radeon_dp_link_train(encoder, connector);
-			if (ASIC_IS_DCE4(rdev))
+			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
@@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
+	 * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
+	 * so there use linkb, otherwise the internal eDP panel will stay dark.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
+	if (ASIC_IS_DCE31(rdev)) {
 		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+		    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
 		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
 			enc_idx = (dig->linkb) ? 1 : 0;
 		else
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 527b9d19d..6b7c0abe4 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
 			    (rdev->family == CHIP_RS740)  ||	\
 			    (rdev->family >= CHIP_R600))
 #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
+#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
 #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
 #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
 #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \

base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d
-- 
2.47.3

Re: [PATCH v4] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Alex Deucher]

On Thu, May 28, 2026 at 3:39 AM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
> (RV770/DCE3.1) with a 2560x1440 internal panel on an internal
> DisplayPort path. Without this fix the display stays dark under KMS.
>
> The same problem already exists for iMac10,1 and iMac11,2. Three fixes:
>
> 1. Introduce ASIC_IS_DCE31() for CHIP_RV770 and newer. Note that
>    CHIP_RV770 precedes CHIP_RV730 in the enum, so ASIC_IS_DCE31()
>    subsumes ASIC_IS_DCE32().
>
> 2. Extend the Link B encoder quirk from ASIC_IS_DCE32() to
>    ASIC_IS_DCE31() and add iMac11,1 to the DMI list.
>
> 3. The 2560x1440 panel needs RADEON_PLL_USE_FRAC_FB_DIV and
>    ATOM_ENCODER_CMD_DP_VIDEO_ON. These are limited to iMac11,1
>    via dmi_match() to avoid affecting other DCE3.1 boards.
>
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> ---
>  drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
>  drivers/gpu/drm/radeon/atombios_encoders.c | 11 ++++++-----
>  drivers/gpu/drm/radeon/radeon.h            |  1 +
>  3 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 2fc0334e0..075eba2d4 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -24,6 +24,8 @@
>   *          Alex Deucher
>   */
>
> +#include <linux/dmi.h>
> +
>  #include <drm/drm_fixed.h>
>  #include <drm/drm_fourcc.h>
>  #include <drm/drm_framebuffer.h>
> @@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>                 if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
>                     && !radeon_crtc->ss_enabled)
>                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> -               if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
> +               if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> +                   && mode->clock > 165000)
>                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
>         } else {
>                 radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> index 5cfd8fcfa..4de60559f 100644
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>                         radeon_dp_link_train(encoder, connector);
> -                       if (ASIC_IS_DCE4(rdev))
> +                       if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
>                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>                 }
>                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> @@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
>         }
>
>         /*
> -        * On DCE32 any encoder can drive any block so usually just use crtc id,
> -        * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
> -        * otherwise the internal eDP panel will stay dark.
> +        * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
> +        * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
> +        * so there use linkb, otherwise the internal eDP panel will stay dark.
>          */
> -       if (ASIC_IS_DCE32(rdev)) {
> +       if (ASIC_IS_DCE31(rdev)) {

This will change the routing for DCE3.1 as well.  Probably best to do
something like:

if (dmi_match(DMI_PRODUCT_NAME, "iMac11,1")) {
    enc_idx = (dig->linkb) ? 1 : 0;
    goto assigned;
}

before or after the DCE32() block.

>                 if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> +                   dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
>                     dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
>                         enc_idx = (dig->linkb) ? 1 : 0;
>                 else
> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> index 527b9d19d..6b7c0abe4 100644
> --- a/drivers/gpu/drm/radeon/radeon.h
> +++ b/drivers/gpu/drm/radeon/radeon.h
> @@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
>                             (rdev->family == CHIP_RS740)  ||    \
>                             (rdev->family >= CHIP_R600))
>  #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
> +#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
>  #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
>  #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
>  #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
>
> base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d
> --
> 2.47.3
>

Re: [PATCH v4] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

Good morning,

I'll make that adjustment, shouldn't I just regroup all three iMac
machines in one if statement?

Am Do., 28. Mai 2026 um 20:53 Uhr schrieb Alex Deucher <alexdeucher@gmail.com>:
>
> On Thu, May 28, 2026 at 3:39 AM Gilles Risch <gilles.risch@gmail.com> wrote:
> >
> > The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
> > (RV770/DCE3.1) with a 2560x1440 internal panel on an internal
> > DisplayPort path. Without this fix the display stays dark under KMS.
> >
> > The same problem already exists for iMac10,1 and iMac11,2. Three fixes:
> >
> > 1. Introduce ASIC_IS_DCE31() for CHIP_RV770 and newer. Note that
> >    CHIP_RV770 precedes CHIP_RV730 in the enum, so ASIC_IS_DCE31()
> >    subsumes ASIC_IS_DCE32().
> >
> > 2. Extend the Link B encoder quirk from ASIC_IS_DCE32() to
> >    ASIC_IS_DCE31() and add iMac11,1 to the DMI list.
> >
> > 3. The 2560x1440 panel needs RADEON_PLL_USE_FRAC_FB_DIV and
> >    ATOM_ENCODER_CMD_DP_VIDEO_ON. These are limited to iMac11,1
> >    via dmi_match() to avoid affecting other DCE3.1 boards.
> >
> > Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> > ---
> >  drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
> >  drivers/gpu/drm/radeon/atombios_encoders.c | 11 ++++++-----
> >  drivers/gpu/drm/radeon/radeon.h            |  1 +
> >  3 files changed, 11 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> > index 2fc0334e0..075eba2d4 100644
> > --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> > +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> > @@ -24,6 +24,8 @@
> >   *          Alex Deucher
> >   */
> >
> > +#include <linux/dmi.h>
> > +
> >  #include <drm/drm_fixed.h>
> >  #include <drm/drm_fourcc.h>
> >  #include <drm/drm_framebuffer.h>
> > @@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
> >                 if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
> >                     && !radeon_crtc->ss_enabled)
> >                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> > -               if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
> > +               if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> > +                   && mode->clock > 165000)
> >                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> >         } else {
> >                 radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
> > diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> > index 5cfd8fcfa..4de60559f 100644
> > --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> > +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> > @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
> >                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
> >                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
> >                         radeon_dp_link_train(encoder, connector);
> > -                       if (ASIC_IS_DCE4(rdev))
> > +                       if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> >                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
> >                 }
> >                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> > @@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
> >         }
> >
> >         /*
> > -        * On DCE32 any encoder can drive any block so usually just use crtc id,
> > -        * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
> > -        * otherwise the internal eDP panel will stay dark.
> > +        * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
> > +        * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
> > +        * so there use linkb, otherwise the internal eDP panel will stay dark.
> >          */
> > -       if (ASIC_IS_DCE32(rdev)) {
> > +       if (ASIC_IS_DCE31(rdev)) {
>
> This will change the routing for DCE3.1 as well.  Probably best to do
> something like:
>
> if (dmi_match(DMI_PRODUCT_NAME, "iMac11,1")) {
>     enc_idx = (dig->linkb) ? 1 : 0;
>     goto assigned;
> }
>
> before or after the DCE32() block.
>
> >                 if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> > +                   dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
> >                     dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
> >                         enc_idx = (dig->linkb) ? 1 : 0;
> >                 else
> > diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> > index 527b9d19d..6b7c0abe4 100644
> > --- a/drivers/gpu/drm/radeon/radeon.h
> > +++ b/drivers/gpu/drm/radeon/radeon.h
> > @@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
> >                             (rdev->family == CHIP_RS740)  ||    \
> >                             (rdev->family >= CHIP_R600))
> >  #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
> > +#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
> >  #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
> >  #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
> >  #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
> >
> > base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d
> > --
> > 2.47.3
> >



-- 
Gilles

Sent from my Commodore C=64

Re: [PATCH v4] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Alex Deucher]

On Fri, May 29, 2026 at 3:43 AM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> Good morning,
>
> I'll make that adjustment, shouldn't I just regroup all three iMac
> machines in one if statement?

Yeah, that works too.

Alex

>
> Am Do., 28. Mai 2026 um 20:53 Uhr schrieb Alex Deucher <alexdeucher@gmail.com>:
> >
> > On Thu, May 28, 2026 at 3:39 AM Gilles Risch <gilles.risch@gmail.com> wrote:
> > >
> > > The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
> > > (RV770/DCE3.1) with a 2560x1440 internal panel on an internal
> > > DisplayPort path. Without this fix the display stays dark under KMS.
> > >
> > > The same problem already exists for iMac10,1 and iMac11,2. Three fixes:
> > >
> > > 1. Introduce ASIC_IS_DCE31() for CHIP_RV770 and newer. Note that
> > >    CHIP_RV770 precedes CHIP_RV730 in the enum, so ASIC_IS_DCE31()
> > >    subsumes ASIC_IS_DCE32().
> > >
> > > 2. Extend the Link B encoder quirk from ASIC_IS_DCE32() to
> > >    ASIC_IS_DCE31() and add iMac11,1 to the DMI list.
> > >
> > > 3. The 2560x1440 panel needs RADEON_PLL_USE_FRAC_FB_DIV and
> > >    ATOM_ENCODER_CMD_DP_VIDEO_ON. These are limited to iMac11,1
> > >    via dmi_match() to avoid affecting other DCE3.1 boards.
> > >
> > > Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> > > ---
> > >  drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
> > >  drivers/gpu/drm/radeon/atombios_encoders.c | 11 ++++++-----
> > >  drivers/gpu/drm/radeon/radeon.h            |  1 +
> > >  3 files changed, 11 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> > > index 2fc0334e0..075eba2d4 100644
> > > --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> > > +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> > > @@ -24,6 +24,8 @@
> > >   *          Alex Deucher
> > >   */
> > >
> > > +#include <linux/dmi.h>
> > > +
> > >  #include <drm/drm_fixed.h>
> > >  #include <drm/drm_fourcc.h>
> > >  #include <drm/drm_framebuffer.h>
> > > @@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
> > >                 if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
> > >                     && !radeon_crtc->ss_enabled)
> > >                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> > > -               if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
> > > +               if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> > > +                   && mode->clock > 165000)
> > >                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> > >         } else {
> > >                 radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
> > > diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> > > index 5cfd8fcfa..4de60559f 100644
> > > --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> > > +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> > > @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
> > >                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
> > >                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
> > >                         radeon_dp_link_train(encoder, connector);
> > > -                       if (ASIC_IS_DCE4(rdev))
> > > +                       if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> > >                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
> > >                 }
> > >                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> > > @@ -2123,12 +2123,13 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
> > >         }
> > >
> > >         /*
> > > -        * On DCE32 any encoder can drive any block so usually just use crtc id,
> > > -        * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
> > > -        * otherwise the internal eDP panel will stay dark.
> > > +        * On DCE31 and DCE32 any encoder can drive any block so usually just use crtc id,
> > > +        * but Apple thinks different at least on iMac10,1, iMac11,1 and iMac11,2,
> > > +        * so there use linkb, otherwise the internal eDP panel will stay dark.
> > >          */
> > > -       if (ASIC_IS_DCE32(rdev)) {
> > > +       if (ASIC_IS_DCE31(rdev)) {
> >
> > This will change the routing for DCE3.1 as well.  Probably best to do
> > something like:
> >
> > if (dmi_match(DMI_PRODUCT_NAME, "iMac11,1")) {
> >     enc_idx = (dig->linkb) ? 1 : 0;
> >     goto assigned;
> > }
> >
> > before or after the DCE32() block.
> >
> > >                 if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> > > +                   dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
> > >                     dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
> > >                         enc_idx = (dig->linkb) ? 1 : 0;
> > >                 else
> > > diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> > > index 527b9d19d..6b7c0abe4 100644
> > > --- a/drivers/gpu/drm/radeon/radeon.h
> > > +++ b/drivers/gpu/drm/radeon/radeon.h
> > > @@ -2625,6 +2625,7 @@ void r100_pll_errata_after_index(struct radeon_device *rdev);
> > >                             (rdev->family == CHIP_RS740)  ||    \
> > >                             (rdev->family >= CHIP_R600))
> > >  #define ASIC_IS_DCE3(rdev) ((rdev->family >= CHIP_RV620))
> > > +#define ASIC_IS_DCE31(rdev) ((rdev->family >= CHIP_RV770))
> > >  #define ASIC_IS_DCE32(rdev) ((rdev->family >= CHIP_RV730))
> > >  #define ASIC_IS_DCE4(rdev) ((rdev->family >= CHIP_CEDAR))
> > >  #define ASIC_IS_DCE41(rdev) ((rdev->family >= CHIP_PALM) && \
> > >
> > > base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d
> > > --
> > > 2.47.3
> > >
>
>
>
> --
> Gilles
>
> Sent from my Commodore C=64

[PATCH v5] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
(RV770/DCE3.1) with a 2560x1440 internal panel on an internal
DisplayPort path. Without this fix the display stays dark under KMS.

This machine suffers from the same issue as iMac10,1 and iMac11,2:
Apple routes the internal display through Link B of the DIG encoder
instead of Link A. Add iMac11,1 to the existing DMI quirk and move
the Apple-specific encoder assignment into its own block, independent
of the DCE version check.

Additionally, the 2560x1440 panel requires RADEON_PLL_USE_FRAC_FB_DIV
and ATOM_ENCODER_CMD_DP_VIDEO_ON, limited to iMac11,1 via dmi_match()
to avoid affecting other boards.

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
 drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
 drivers/gpu/drm/radeon/atombios_encoders.c | 23 ++++++++++++----------
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0..075eba2d4 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -24,6 +24,8 @@
  *          Alex Deucher
  */
 
+#include <linux/dmi.h>
+
 #include <drm/drm_fixed.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
@@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
+		    && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 5cfd8fcfa..8b3f8303a 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
 			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
 			radeon_dp_link_train(encoder, connector);
-			if (ASIC_IS_DCE4(rdev))
+			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
@@ -2123,17 +2123,20 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * Apple routes the internal eDP panel through Link B of the DIG encoder
+	 * instead of Link A on the iMac10,1, iMac11,1 and iMac11,2.
+	 * Use linkb to avoid a dark display.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
-		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
-		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
-			enc_idx = (dig->linkb) ? 1 : 0;
-		else
-			enc_idx = radeon_crtc->crtc_id;
+	if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+	    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
+	    dmi_match(DMI_PRODUCT_NAME, "iMac11,2")) {
+		enc_idx = (dig->linkb) ? 1 : 0;
+		goto assigned;
+	}
 
+	/* on DCE32 and encoder can driver any block so just crtc id */
+	if (ASIC_IS_DCE32(rdev)) {
+		enc_idx = radeon_crtc->crtc_id;
 		goto assigned;
 	}
 
-- 
2.47.3

Re: [PATCH v5] drm/radeon: fix internal display on iMac11,1 (RV770/DCE3.1)

[Gilles Risch]

Hello,

gentle ping on this v5 patch — is there anything else needed to get this 
merged?

Regards,
Gilles


On 01.06.26 23:19, Gilles Risch wrote:
> The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
> (RV770/DCE3.1) with a 2560x1440 internal panel on an internal
> DisplayPort path. Without this fix the display stays dark under KMS.
>
> This machine suffers from the same issue as iMac10,1 and iMac11,2:
> Apple routes the internal display through Link B of the DIG encoder
> instead of Link A. Add iMac11,1 to the existing DMI quirk and move
> the Apple-specific encoder assignment into its own block, independent
> of the DCE version check.
>
> Additionally, the 2560x1440 panel requires RADEON_PLL_USE_FRAC_FB_DIV
> and ATOM_ENCODER_CMD_DP_VIDEO_ON, limited to iMac11,1 via dmi_match()
> to avoid affecting other boards.
>
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
> ---
>   drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
>   drivers/gpu/drm/radeon/atombios_encoders.c | 23 ++++++++++++----------
>   2 files changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 2fc0334e0..075eba2d4 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -24,6 +24,8 @@
>    *          Alex Deucher
>    */
>   
> +#include <linux/dmi.h>
> +
>   #include <drm/drm_fixed.h>
>   #include <drm/drm_fourcc.h>
>   #include <drm/drm_framebuffer.h>
> @@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>   		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
>   		    && !radeon_crtc->ss_enabled)
>   			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> -		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
> +		if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> +		    && mode->clock > 165000)
>   			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
>   	} else {
>   		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> index 5cfd8fcfa..8b3f8303a 100644
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>   		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>   			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>   			radeon_dp_link_train(encoder, connector);
> -			if (ASIC_IS_DCE4(rdev))
> +			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
>   				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>   		}
>   		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> @@ -2123,17 +2123,20 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
>   	}
>   
>   	/*
> -	 * On DCE32 any encoder can drive any block so usually just use crtc id,
> -	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
> -	 * otherwise the internal eDP panel will stay dark.
> +	 * Apple routes the internal eDP panel through Link B of the DIG encoder
> +	 * instead of Link A on the iMac10,1, iMac11,1 and iMac11,2.
> +	 * Use linkb to avoid a dark display.
>   	 */
> -	if (ASIC_IS_DCE32(rdev)) {
> -		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> -		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
> -			enc_idx = (dig->linkb) ? 1 : 0;
> -		else
> -			enc_idx = radeon_crtc->crtc_id;
> +	if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> +	    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
> +	    dmi_match(DMI_PRODUCT_NAME, "iMac11,2")) {
> +		enc_idx = (dig->linkb) ? 1 : 0;
> +		goto assigned;
> +	}
>   
> +	/* on DCE32 and encoder can driver any block so just crtc id */
> +	if (ASIC_IS_DCE32(rdev)) {
> +		enc_idx = radeon_crtc->crtc_id;
>   		goto assigned;
>   	}
>   

[PATCH v6] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Gilles Risch]

The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
(RV770/DCE3.1) with a 2560x1440 internal panel on an internal
DisplayPort path. Without this fix the display stays dark under KMS.

This machine suffers from the same issue as iMac10,1 and iMac11,2:
Apple routes the internal display through Link B of the DIG encoder
instead of Link A. Add iMac11,1 to the existing DMI quirk and move
the Apple-specific encoder assignment into its own block, independent
of the DCE version check.

Additionally, the 2560x1440 panel requires RADEON_PLL_USE_FRAC_FB_DIV
and ATOM_ENCODER_CMD_DP_VIDEO_ON, limited to iMac11,1 via dmi_match()
to avoid affecting other boards.

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>

Good morning,

this is v6 of the patch, rebased on top of amd-staging-drm-next
(agd5f/linux).

There are no functional or code changes since v5.

Regarding Lukas Wunner's previous Reviewed-by (which was provided on v2),
I have kept him in CC so he can confirm if his review still stands given
the changes between v2 and v5.

Could you have a look at this when you have a spare moment?

Regards,
Gilles

Changes in v6:
- Rebased on amd-staging-drm-next (no functional/code changes since v5)
---
 drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
 drivers/gpu/drm/radeon/atombios_encoders.c | 23 ++++++++++++----------
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 2fc0334e0d6c..075eba2d47f3 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -24,6 +24,8 @@
  *          Alex Deucher
  */
 
+#include <linux/dmi.h>
+
 #include <drm/drm_fixed.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
@@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
 		    && !radeon_crtc->ss_enabled)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
-		if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
+		if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
+		    && mode->clock > 165000)
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 	} else {
 		radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 5cfd8fcfa5e8..8b3f8303a967 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
 			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
 			radeon_dp_link_train(encoder, connector);
-			if (ASIC_IS_DCE4(rdev))
+			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
@@ -2123,17 +2123,20 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
 	}
 
 	/*
-	 * On DCE32 any encoder can drive any block so usually just use crtc id,
-	 * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
-	 * otherwise the internal eDP panel will stay dark.
+	 * Apple routes the internal eDP panel through Link B of the DIG encoder
+	 * instead of Link A on the iMac10,1, iMac11,1 and iMac11,2.
+	 * Use linkb to avoid a dark display.
 	 */
-	if (ASIC_IS_DCE32(rdev)) {
-		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
-		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
-			enc_idx = (dig->linkb) ? 1 : 0;
-		else
-			enc_idx = radeon_crtc->crtc_id;
+	if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
+	    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
+	    dmi_match(DMI_PRODUCT_NAME, "iMac11,2")) {
+		enc_idx = (dig->linkb) ? 1 : 0;
+		goto assigned;
+	}
 
+	/* on DCE32 and encoder can driver any block so just crtc id */
+	if (ASIC_IS_DCE32(rdev)) {
+		enc_idx = radeon_crtc->crtc_id;
 		goto assigned;
 	}
 

base-commit: 21c50d41af7c46e138b542dba2dcf6d2a978ae99
-- 
2.47.3

Re: [PATCH v6] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Missing ATOM_ENCODER_CMD_DP_VIDEO_OFF for iMac11,1 in DPMS disable path
--

--- Patch [1]: [PATCH v6] drm/radeon: fix internal display on iMac11, 1  (RV770/DCE3.1) ---
commit 6714fa0de0a69a7e28cd2cf7fe610715f038e79d
Author: Gilles Risch <gilles.risch@gmail.com>
drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

This commit adds a DMI quirk to route the iMac11,1 internal display
through Link B of the DIG encoder. It also sets the FRAC_FB_DIV PLL flag
and enables DP_VIDEO_ON explicitly for this hardware to fix a blank screen
issue.

> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c

[ ... ]

> @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>  		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>  			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>  			radeon_dp_link_train(encoder, connector);
> -			if (ASIC_IS_DCE4(rdev))
> +			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
>  				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>  		}

[Severity: Medium]
Should the corresponding disable paths (standby, suspend, off) also
include the iMac11,1 DMI check for turning the video off?

Later in radeon_atom_encoder_dpms_dig(), the ATOM_ENCODER_CMD_DP_VIDEO_OFF
command is only sent if ASIC_IS_DCE4(rdev):

    case DRM_MODE_DPMS_STANDBY:
    case DRM_MODE_DPMS_SUSPEND:
    case DRM_MODE_DPMS_OFF:

        if (ASIC_IS_DCE4(rdev)) {
            if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
                atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
        }

Does the iMac11,1 (which is DCE3.1) need ATOM_ENCODER_CMD_DP_VIDEO_OFF
sent here to properly stop the stream before the link is disabled?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260817004326.3192-1-gilles.risch@gmail.com?part=1

Re: [PATCH v6] drm/radeon: fix internal display on iMac11,1 (RV770/DCE3.1)

[Lukas Wunner]

On Mon, Aug 17, 2026 at 02:43:26AM +0200, Gilles Risch wrote:
> The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
> (RV770/DCE3.1) with a 2560x1440 internal panel on an internal
> DisplayPort path. Without this fix the display stays dark under KMS.
> 
> This machine suffers from the same issue as iMac10,1 and iMac11,2:
> Apple routes the internal display through Link B of the DIG encoder
> instead of Link A. Add iMac11,1 to the existing DMI quirk and move
> the Apple-specific encoder assignment into its own block, independent
> of the DCE version check.
> 
> Additionally, the 2560x1440 panel requires RADEON_PLL_USE_FRAC_FB_DIV
> and ATOM_ENCODER_CMD_DP_VIDEO_ON, limited to iMac11,1 via dmi_match()
> to avoid affecting other boards.
> 
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>

Reviewed-by: Lukas Wunner <lukas@wunner.de>

> Good morning,
> 
> this is v6 of the patch, rebased on top of amd-staging-drm-next
> (agd5f/linux).
> 
> There are no functional or code changes since v5.
> 
> Regarding Lukas Wunner's previous Reviewed-by (which was provided on v2),
> I have kept him in CC so he can confirm if his review still stands given
> the changes between v2 and v5.
> 
> Could you have a look at this when you have a spare moment?
> 
> Regards,
> Gilles
> 
> Changes in v6:
> - Rebased on amd-staging-drm-next (no functional/code changes since v5)
> ---

Put additional information like this below the three dashes
so that it's not committed to the git repo when the maintainer
applies your patch.

> -	if (ASIC_IS_DCE32(rdev)) {
> -		if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> -		    dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
> -			enc_idx = (dig->linkb) ? 1 : 0;
> -		else
> -			enc_idx = radeon_crtc->crtc_id;
> +	if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> +	    dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
> +	    dmi_match(DMI_PRODUCT_NAME, "iMac11,2")) {
> +		enc_idx = (dig->linkb) ? 1 : 0;
> +		goto assigned;
> +	}

Nit:
If the number of dmi_match() calls exceeds one or two, for readability
it's usually a good idea to create a table and match against that with
dmi_check_system().

Thanks,

Lukas

Re: [PATCH v6] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[Alex Deucher]

Applied.  Thanks!

Alex

On Sun, Aug 16, 2026 at 8:43 PM Gilles Risch <gilles.risch@gmail.com> wrote:
>
> The Apple iMac11,1 (27-inch, Late 2009) uses a Mobility Radeon HD 4850
> (RV770/DCE3.1) with a 2560x1440 internal panel on an internal
> DisplayPort path. Without this fix the display stays dark under KMS.
>
> This machine suffers from the same issue as iMac10,1 and iMac11,2:
> Apple routes the internal display through Link B of the DIG encoder
> instead of Link A. Add iMac11,1 to the existing DMI quirk and move
> the Apple-specific encoder assignment into its own block, independent
> of the DCE version check.
>
> Additionally, the 2560x1440 panel requires RADEON_PLL_USE_FRAC_FB_DIV
> and ATOM_ENCODER_CMD_DP_VIDEO_ON, limited to iMac11,1 via dmi_match()
> to avoid affecting other boards.
>
> Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
>
> Good morning,
>
> this is v6 of the patch, rebased on top of amd-staging-drm-next
> (agd5f/linux).
>
> There are no functional or code changes since v5.
>
> Regarding Lukas Wunner's previous Reviewed-by (which was provided on v2),
> I have kept him in CC so he can confirm if his review still stands given
> the changes between v2 and v5.
>
> Could you have a look at this when you have a spare moment?
>
> Regards,
> Gilles
>
> Changes in v6:
> - Rebased on amd-staging-drm-next (no functional/code changes since v5)
> ---
>  drivers/gpu/drm/radeon/atombios_crtc.c     |  5 ++++-
>  drivers/gpu/drm/radeon/atombios_encoders.c | 23 ++++++++++++----------
>  2 files changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 2fc0334e0d6c..075eba2d47f3 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -24,6 +24,8 @@
>   *          Alex Deucher
>   */
>
> +#include <linux/dmi.h>
> +
>  #include <drm/drm_fixed.h>
>  #include <drm/drm_fourcc.h>
>  #include <drm/drm_framebuffer.h>
> @@ -594,7 +596,8 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
>                 if (((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))
>                     && !radeon_crtc->ss_enabled)
>                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
> -               if (ASIC_IS_DCE32(rdev) && mode->clock > 165000)
> +               if ((ASIC_IS_DCE32(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
> +                   && mode->clock > 165000)
>                         radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
>         } else {
>                 radeon_crtc->pll_flags |= RADEON_PLL_LEGACY;
> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> index 5cfd8fcfa5e8..8b3f8303a967 100644
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c
> @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>                 if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>                         /* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>                         radeon_dp_link_train(encoder, connector);
> -                       if (ASIC_IS_DCE4(rdev))
> +                       if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
>                                 atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>                 }
>                 if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
> @@ -2123,17 +2123,20 @@ int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx)
>         }
>
>         /*
> -        * On DCE32 any encoder can drive any block so usually just use crtc id,
> -        * but Apple thinks different at least on iMac10,1 and iMac11,2, so there use linkb,
> -        * otherwise the internal eDP panel will stay dark.
> +        * Apple routes the internal eDP panel through Link B of the DIG encoder
> +        * instead of Link A on the iMac10,1, iMac11,1 and iMac11,2.
> +        * Use linkb to avoid a dark display.
>          */
> -       if (ASIC_IS_DCE32(rdev)) {
> -               if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> -                   dmi_match(DMI_PRODUCT_NAME, "iMac11,2"))
> -                       enc_idx = (dig->linkb) ? 1 : 0;
> -               else
> -                       enc_idx = radeon_crtc->crtc_id;
> +       if (dmi_match(DMI_PRODUCT_NAME, "iMac10,1") ||
> +           dmi_match(DMI_PRODUCT_NAME, "iMac11,1") ||
> +           dmi_match(DMI_PRODUCT_NAME, "iMac11,2")) {
> +               enc_idx = (dig->linkb) ? 1 : 0;
> +               goto assigned;
> +       }
>
> +       /* on DCE32 and encoder can driver any block so just crtc id */
> +       if (ASIC_IS_DCE32(rdev)) {
> +               enc_idx = radeon_crtc->crtc_id;
>                 goto assigned;
>         }
>
>
> base-commit: 21c50d41af7c46e138b542dba2dcf6d2a978ae99
> --
> 2.47.3
>