[PATCH v2 1/3] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0

[PATCH v2 1/3] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0

[Maciej Kucharek]

On MacBookPros with switchable graphics, the firmware puts VRAM at MC
address 0 when the iGPU is enabled.  The EFI stub enables the iGPU on
these machines through apple_set_os().  On a MacBookPro11,5 (Radeon R9
M370X, 1002:6821, subsystem 106b:0149), the driver adopts this layout
at init:

  MC_VM_FB_LOCATION=0x007f0000, HDP_NONSURFACE_BASE=0
  VRAM at 0x0-0x7fffffff, GART table at 0x1400000

The driver posts the ASIC again on S3 resume and after a GPU reset.
The VBIOS asic_init table then moves VRAM back to the VBIOS default:

  MC_VM_FB_LOCATION=0xf47ff400, HDP_NONSURFACE_BASE=0xf4000000

gmc_v6_0 does not reprogram these registers.  The GART table is then
no longer in VRAM, and the gfx ring test times out:

  amdgpu: ring gfx test failed (-110)
  amdgpu: resume of IP block <gfx_v6_0> failed -110

Reset and post the ASIC at driver load on Apple boards with VRAM at 0.
The driver then uses the VBIOS layout (VRAM at 0xf400000000) from the
start, and later posts keep it.  After the reset, FB_BASE is not 0, so
a module reload does not reset the ASIC again.

The test is the same one that commit c7f44ec5c4ec ("drm/amdgpu: make
Mac FB workaround generic") uses: an Apple subsystem vendor and VRAM at
0.  The VI quirk for the MacBookPro14,3 resets at load for the same
reason:

  commit a22e5e4f2ebb ("drm/amdgpu: reset VI ASIC on MacBookPro14,3")

Other Apple SI boards get the same reset if FB_BASE reads 0 at load.

Tested on a MacBookPro11,5 with 7.2.5 and this patch: the panel comes
up at boot, and 4 of 4 deep S3 cycles resume.  Without the patch, S3
resume fails every time.  The GPU reset path is not tested.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/5978
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/si.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/si.c b/drivers/gpu/drm/amd/amdgpu/si.c
index 0adfd4b10..e5e590425 100644
--- a/drivers/gpu/drm/amd/amdgpu/si.c
+++ b/drivers/gpu/drm/amd/amdgpu/si.c
@@ -1512,6 +1512,16 @@ static void si_invalidate_hdp(struct amdgpu_device *adev,
 
 static bool si_need_reset_on_init(struct amdgpu_device *adev)
 {
+	/*
+	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
+	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
+	 * the vbios default, so reset and post on load to start with the
+	 * vbios layout.
+	 */
+	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+	    !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
+		return true;
+
 	return false;
 }
 
-- 
2.55.0

Re: [PATCH v2 1/3] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0

[Brad Drury]

Hi Maciej,

I tested this patch on a second MacBookPro11,5 (Radeon R9 M370X, Verde,
1002:6821, subsystem 106b:0149). Here the dGPU is a headless PRIME
offload GPU and the panel is on i915. The kernel is linux 7.3-rc7, with
amdgpu rebuilt from that tree with this patch on top and nothing else
changed in amdgpu (amdgpu.si_support=1 radeon.si_support=0,
mem_sleep=deep).

Without the patch, VRAM is at 0 after boot and every S3 resume fails
with "ring gfx test failed (-110)".

With it, amdgpu logs "PCI CONFIG reset" and "GPU posting now..." at
load, and VRAM ends up at 0x000000F400000000. I then ran four S3 cycles:
two on battery and two on AC, from 9 minutes to 13 h 19 min asleep.
After each resume the GART table was still at 0x000000F400000000 and
the kernel log showed no ring timeouts, -110 errors or GPU recovery.
After the last (overnight) resume, DRI_PRIME=1 glxgears (radeonsi) and
vkcube (RADV) ran, and VA-API H.264 encode (VCE) and decode (UVD) both
worked through ffmpeg.

One thing I noticed: on 2 of the 4 resumes, about a second after
resume, vce_v1_0_stop() logged:

  amdgpu 0000:01:00.0: VCE busy: VCE_STATUS=0x2, SRBM_STATUS2=0x80

VCE encode worked straight afterwards, so it doesn't seem to break
anything. I didn't see it in about 11 resumes with a local workaround
that kept VRAM at 0, so it may come with the new layout, but I haven't
looked further. Mentioning it in case it's known.

This supersedes the gmc6 patch I sent on 20 Oct for the same failure:
https://lore.kernel.org/amd-gfx/20261020-gmc6-writes-only-v3-v1-1-70730a302504@gmail.com/

Tested-by: Brad Drury <drury.brad@gmail.com> # MacBookPro11,5, Radeon R9 M370X

Thanks,
Brad

Re: [PATCH v2 1/3] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0

[Timur Kristóf]

On 2026. október 22., csütörtök 9:36:38 közép-európai téli idő Brad Drury 
wrote:
> One thing I noticed: on 2 of the 4 resumes, about a second after
> resume, vce_v1_0_stop() logged:
> 
>   amdgpu 0000:01:00.0: VCE busy: VCE_STATUS=0x2, SRBM_STATUS2=0x80
> 
> VCE encode worked straight afterwards, so it doesn't seem to break
> anything.

The following patch should fix that:
"drm/amdgpu/vce1: Fix checking whether VCE1 is idle"
https://lists.freedesktop.org/archives/amd-gfx/2026-October/154367.html

Best regards,
Timur

[PATCH v2 2/3] drm/amdgpu: reset CIK ASIC on Apple boards with VRAM at 0

[Maciej Kucharek]

On MacBookPros with switchable graphics, the firmware puts VRAM at MC
address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
reset) moves VRAM back to the VBIOS default.  The SI fix resets and
posts the ASIC at load, so the driver uses the VBIOS layout from the
start:

  "drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0"

No MacBookPro has a CIK GPU, and no affected CIK board is known.  Add
the same test to cik_need_reset_on_init(), so that SI, CIK and VI
handle this firmware layout in the same way.  gmc_v7_0 reads
MC_VM_FB_LOCATION once at init and does not reprogram it.  A CIK board
with VRAM at 0 therefore has the same problem as the SI boards.

After the reset, FB_BASE is not 0, so the new test does not fire again
on a module reload.

Only compile-tested.

Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/cik.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/cik.c b/drivers/gpu/drm/amd/amdgpu/cik.c
index d29991a4a..e1029239b 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik.c
@@ -1927,6 +1927,16 @@ static bool cik_need_reset_on_init(struct amdgpu_device *adev)
 {
 	u32 clock_cntl, pc;
 
+	/*
+	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
+	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
+	 * the vbios default, so reset and post on load to start with the
+	 * vbios layout.
+	 */
+	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+	    !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
+		return true;
+
 	if (adev->flags & AMD_IS_APU)
 		return false;
 
-- 
2.55.0

[PATCH v2 3/3] drm/amdgpu: reset VI ASIC on Apple boards with VRAM at 0

[Maciej Kucharek]

On MacBookPros with switchable graphics, the firmware puts VRAM at MC
address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
reset) moves VRAM back to the VBIOS default.  gmc_v8_0 reads
MC_VM_FB_LOCATION once at init and reprograms it only on SR-IOV.  On
bare metal, the driver then keeps using the old layout.

vi_reset_quirks[] handles this for the MacBookPro14,3 by PCI ID:

  commit a22e5e4f2ebb ("drm/amdgpu: reset VI ASIC on MacBookPro14,3")

Add the test that SI and CIK use: an Apple subsystem vendor and VRAM at
0.  Other Polaris MacBookPros then get the same reset at load, for
example the MacBookPro13,3 if its firmware leaves VRAM at 0.  These
boards are not tested.

Keep vi_reset_quirks[].  Its MacBookPro15,1 entries fix a different
failure, a module reload after S3:

  commit a5be7ad8f5f0 ("drm/amdgpu: reset VI ASIC on MacBookPro15,1")

VRAM is not at 0 at that point, so the new test may not cover it.

After the reset, FB_BASE is not 0, so the new test does not fire again
on a module reload.

Only compile-tested.

Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/vi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
index a0435fd55..cad6bbfce 100644
--- a/drivers/gpu/drm/amd/amdgpu/vi.c
+++ b/drivers/gpu/drm/amd/amdgpu/vi.c
@@ -1405,6 +1405,16 @@ static bool vi_need_reset_on_init(struct amdgpu_device *adev)
 	unsigned int i;
 	u32 clock_cntl, pc;
 
+	/*
+	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
+	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
+	 * the vbios default, so reset and post on load to start with the
+	 * vbios layout.
+	 */
+	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+	    !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
+		return true;
+
 	for (i = 0; i < ARRAY_SIZE(vi_reset_quirks); i++)
 		if (adev->pdev->device == vi_reset_quirks[i].device &&
 		    adev->pdev->subsystem_vendor == vi_reset_quirks[i].subsystem_vendor &&
-- 
2.55.0

Re: [PATCH v2 3/3] drm/amdgpu: reset VI ASIC on Apple boards with VRAM at 0

[Alex Deucher]

On Thu, Oct 15, 2026 at 9:06 AM Maciej Kucharek <qchcio@gmail.com> wrote:
>
> On MacBookPros with switchable graphics, the firmware puts VRAM at MC
> address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
> reset) moves VRAM back to the VBIOS default.  gmc_v8_0 reads
> MC_VM_FB_LOCATION once at init and reprograms it only on SR-IOV.  On
> bare metal, the driver then keeps using the old layout.
>
> vi_reset_quirks[] handles this for the MacBookPro14,3 by PCI ID:
>
>   commit a22e5e4f2ebb ("drm/amdgpu: reset VI ASIC on MacBookPro14,3")
>
> Add the test that SI and CIK use: an Apple subsystem vendor and VRAM at
> 0.  Other Polaris MacBookPros then get the same reset at load, for
> example the MacBookPro13,3 if its firmware leaves VRAM at 0.  These
> boards are not tested.
>
> Keep vi_reset_quirks[].  Its MacBookPro15,1 entries fix a different
> failure, a module reload after S3:
>
>   commit a5be7ad8f5f0 ("drm/amdgpu: reset VI ASIC on MacBookPro15,1")
>
> VRAM is not at 0 at that point, so the new test may not cover it.
>
> After the reset, FB_BASE is not 0, so the new test does not fire again
> on a module reload.
>
> Only compile-tested.
>
> Suggested-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: stable@vger.kernel.org
> Assisted-by: Claude:claude-opus-5-5
> Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/vi.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
> index a0435fd55..cad6bbfce 100644
> --- a/drivers/gpu/drm/amd/amdgpu/vi.c
> +++ b/drivers/gpu/drm/amd/amdgpu/vi.c
> @@ -1405,6 +1405,16 @@ static bool vi_need_reset_on_init(struct amdgpu_device *adev)
>         unsigned int i;
>         u32 clock_cntl, pc;
>
> +       /*
> +        * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
> +        * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
> +        * the vbios default, so reset and post on load to start with the
> +        * vbios layout.
> +        */
> +       if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
> +           !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
> +               return true;
> +
>         for (i = 0; i < ARRAY_SIZE(vi_reset_quirks); i++)
>                 if (adev->pdev->device == vi_reset_quirks[i].device &&
>                     adev->pdev->subsystem_vendor == vi_reset_quirks[i].subsystem_vendor &&

Please drop the now duplicate quirk handling here.

Thanks,

Alex

> --
> 2.55.0
>

[PATCH v3 1/3] drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0

[Maciej Kucharek]

On MacBookPros with switchable graphics, the firmware puts VRAM at MC
address 0 when the iGPU is enabled.  The EFI stub enables the iGPU on
these machines through apple_set_os().  On a MacBookPro11,5 (Radeon R9
M370X, 1002:6821, subsystem 106b:0149), the driver adopts this layout
at init:

  MC_VM_FB_LOCATION=0x007f0000, HDP_NONSURFACE_BASE=0
  VRAM at 0x0-0x7fffffff, GART table at 0x1400000

The driver posts the ASIC again on S3 resume and after a GPU reset.
The VBIOS asic_init table then moves VRAM back to the VBIOS default:

  MC_VM_FB_LOCATION=0xf47ff400, HDP_NONSURFACE_BASE=0xf4000000

gmc_v6_0 does not reprogram these registers.  The GART table is then
no longer in VRAM, and the gfx ring test times out:

  amdgpu: ring gfx test failed (-110)
  amdgpu: resume of IP block <gfx_v6_0> failed -110

Reset and post the ASIC at driver load on Apple boards with VRAM at 0.
The driver then uses the VBIOS layout (VRAM at 0xf400000000) from the
start, and later posts keep it.  After the reset, FB_BASE is not 0, so
a module reload does not reset the ASIC again.

The test is the same one that commit c7f44ec5c4ec ("drm/amdgpu: make
Mac FB workaround generic") uses: an Apple subsystem vendor and VRAM at
0.  The VI quirk for the MacBookPro14,3 resets at load for the same
reason:

  commit a22e5e4f2ebb ("drm/amdgpu: reset VI ASIC on MacBookPro14,3")

Other Apple SI boards get the same reset if FB_BASE reads 0 at load.

Tested on a MacBookPro11,5 with 7.2.5 and this patch: the panel comes
up at boot, and 4 of 4 deep S3 cycles resume.  Without the patch, S3
resume fails every time.  The GPU reset path is not tested.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/5978
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/si.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/si.c b/drivers/gpu/drm/amd/amdgpu/si.c
index 0adfd4b10..e5e590425 100644
--- a/drivers/gpu/drm/amd/amdgpu/si.c
+++ b/drivers/gpu/drm/amd/amdgpu/si.c
@@ -1512,6 +1512,16 @@ static void si_invalidate_hdp(struct amdgpu_device *adev,
 
 static bool si_need_reset_on_init(struct amdgpu_device *adev)
 {
+	/*
+	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
+	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
+	 * the vbios default, so reset and post on load to start with the
+	 * vbios layout.
+	 */
+	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+	    !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
+		return true;
+
 	return false;
 }
 
-- 
2.55.0

[PATCH v3 2/3] drm/amdgpu: reset CIK ASIC on Apple boards with VRAM at 0

[Maciej Kucharek]

On MacBookPros with switchable graphics, the firmware puts VRAM at MC
address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
reset) moves VRAM back to the VBIOS default.  The SI fix resets and
posts the ASIC at load, so the driver uses the VBIOS layout from the
start:

  "drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0"

No MacBookPro has a CIK GPU, and no affected CIK board is known.  Add
the same test to cik_need_reset_on_init(), so that SI, CIK and VI
handle this firmware layout in the same way.  gmc_v7_0 reads
MC_VM_FB_LOCATION once at init and does not reprogram it.  A CIK board
with VRAM at 0 therefore has the same problem as the SI boards.

After the reset, FB_BASE is not 0, so the new test does not fire again
on a module reload.

Only compile-tested.

Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/cik.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/cik.c b/drivers/gpu/drm/amd/amdgpu/cik.c
index d29991a4a..e1029239b 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik.c
@@ -1927,6 +1927,16 @@ static bool cik_need_reset_on_init(struct amdgpu_device *adev)
 {
 	u32 clock_cntl, pc;
 
+	/*
+	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
+	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
+	 * the vbios default, so reset and post on load to start with the
+	 * vbios layout.
+	 */
+	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+	    !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
+		return true;
+
 	if (adev->flags & AMD_IS_APU)
 		return false;
 
-- 
2.55.0

Re: [PATCH v3 2/3] drm/amdgpu: reset CIK ASIC on Apple boards with VRAM at 0

[Timur Kristóf]

On 2026. október 15., csütörtök 20:18:36 közép-európai téli idő Maciej 
Kucharek wrote:
> On MacBookPros with switchable graphics, the firmware puts VRAM at MC
> address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
> reset) moves VRAM back to the VBIOS default.  The SI fix resets and
> posts the ASIC at load, so the driver uses the VBIOS layout from the
> start:
> 
>   "drm/amdgpu: reset SI ASIC on MacBookPros with VRAM at 0"
> 
> No MacBookPro has a CIK GPU, and no affected CIK board is known.  Add
> the same test to cik_need_reset_on_init(), so that SI, CIK and VI
> handle this firmware layout in the same way. 

Just a side note: some old iMacs have a Bonaire GPU, which is CI.
Not sure if those boards are affected or not, but it definitely won't hurt.

> gmc_v7_0 reads
> MC_VM_FB_LOCATION once at init and does not reprogram it.  A CIK board
> with VRAM at 0 therefore has the same problem as the SI boards.
> 
> After the reset, FB_BASE is not 0, so the new test does not fire again
> on a module reload.
> 
> Only compile-tested.
> 
> Suggested-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: stable@vger.kernel.org
> Assisted-by: Claude:claude-opus-5-5
> Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/cik.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/cik.c
> b/drivers/gpu/drm/amd/amdgpu/cik.c index d29991a4a..e1029239b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/cik.c
> +++ b/drivers/gpu/drm/amd/amdgpu/cik.c
> @@ -1927,6 +1927,16 @@ static bool cik_need_reset_on_init(struct
> amdgpu_device *adev) {
>  	u32 clock_cntl, pc;
> 
> +	/*
> +	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
> +	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back 
to
> +	 * the vbios default, so reset and post on load to start with the
> +	 * vbios layout.
> +	 */
> +	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
> +	    !(RREG32(mmMC_VM_FB_LOCATION) & 
MC_VM_FB_LOCATION__FB_BASE_MASK))
> +		return true;
> +
>  	if (adev->flags & AMD_IS_APU)
>  		return false;

[PATCH v3 3/3] drm/amdgpu: reset VI ASIC on Apple boards with VRAM at 0

[Maciej Kucharek]

On MacBookPros with switchable graphics, the firmware puts VRAM at MC
address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
reset) moves VRAM back to the VBIOS default.  gmc_v8_0 reads
MC_VM_FB_LOCATION once at init and reprograms it only on SR-IOV.  On
bare metal, the driver then keeps using the old layout.

vi_reset_quirks[] resets these boards at load by PCI ID:

  commit a5be7ad8f5f0 ("drm/amdgpu: reset VI ASIC on MacBookPro15,1")
  commit a22e5e4f2ebb ("drm/amdgpu: reset VI ASIC on MacBookPro14,3")

Replace the table with the test that SI and CIK use: an Apple subsystem
vendor and VRAM at 0.  Other Polaris MacBookPros then also get the
reset at load, for example the MacBookPro13,3 if its firmware leaves
VRAM at 0.

On the MacBookPro14,3, MC_VM_FB_LOCATION is 0x007f0000 at load, so the
new test covers it.  The MacBookPro15,1 entries fix a module reload
after S3.  With the reset at first load, later posts keep VRAM where the
driver expects it.  The reload failure on these boards is then expected
to go away, but this is not tested.

After the reset, FB_BASE is not 0, so the new test does not fire again
on a module reload.

Only compile-tested.

Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Andre Eikmeyer <dev@deq.rocks>
Cc: Frederick Morlock <me@freddy.us>
Cc: Francisco Beltrán Millalén <fbeltranmillalen@gmail.com>
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/vi.c | 29 +++++++++--------------------
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
index a0435fd55..999aeb797 100644
--- a/drivers/gpu/drm/amd/amdgpu/vi.c
+++ b/drivers/gpu/drm/amd/amdgpu/vi.c
@@ -1387,30 +1387,19 @@ static uint64_t vi_get_pcie_replay_count(struct amdgpu_device *adev)
 	return (nak_r + nak_g);
 }
 
-struct vi_reset_quirk {
-	u16 device;
-	u16 subsystem_vendor;
-	u16 subsystem_device;
-	u8 revision;
-};
-
-static const struct vi_reset_quirk vi_reset_quirks[] = {
-	{ 0x67ef, PCI_VENDOR_ID_APPLE, 0x0190, 0xe3 }, /* Radeon Pro 555X */
-	{ 0x67ef, PCI_VENDOR_ID_APPLE, 0x018f, 0xc2 }, /* Radeon Pro 560X */
-	{ 0x67ef, PCI_VENDOR_ID_APPLE, 0x017a, 0xc7 }, /* Radeon Pro 555 */
-};
-
 static bool vi_need_reset_on_init(struct amdgpu_device *adev)
 {
-	unsigned int i;
 	u32 clock_cntl, pc;
 
-	for (i = 0; i < ARRAY_SIZE(vi_reset_quirks); i++)
-		if (adev->pdev->device == vi_reset_quirks[i].device &&
-		    adev->pdev->subsystem_vendor == vi_reset_quirks[i].subsystem_vendor &&
-		    adev->pdev->subsystem_device == vi_reset_quirks[i].subsystem_device &&
-		    adev->pdev->revision == vi_reset_quirks[i].revision)
-			return true;
+	/*
+	 * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
+	 * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
+	 * the vbios default, so reset and post on load to start with the
+	 * vbios layout.
+	 */
+	if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
+	    !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
+		return true;
 
 	if (adev->flags & AMD_IS_APU)
 		return false;
-- 
2.55.0

Re: [PATCH v3 3/3] drm/amdgpu: reset VI ASIC on Apple boards with VRAM at 0

[Francisco Beltrán Millalén]

Hi Maciej,

Thanks for the patch.

I applied patch 3 to the 6.18.49 kernel I use on my MacBookPro14,3
(Radeon Pro 555, 1002:67ef, subsystem 106b:017a, rev c7).  The kernel
also carries my unrelated PCI and ACPI patches for this machine.

After a cold boot, amdgpu logs "PCI CONFIG reset" and "GPU posting
now..." while it loads, and VRAM ends up at 0xF400000000.
MC_VM_FB_LOCATION reads 0xf47ff400 through debugfs.  In my tests in
September, a kernel without the reset left VRAM at 0 after a cold boot.

I then suspended to RAM three times with rtcwake.  After each resume
MC_VM_FB_LOCATION was still 0xf47ff400, the screen came back, and the
kernel log showed no VM faults, ring timeouts or GPU recovery.  After
the last one I ran glxgears for a minute and the gfx ring kept going.

I also closed the lid for about ten minutes.  After opening it the
screen came back, MC_VM_FB_LOCATION was 0xf47ff400, and glxgears ran
for a minute without errors.

Before that I had also tried it after a warm reboot, with four rtcwake
cycles and one 45-minute suspend from the idle timer.  After each of
those MC_VM_FB_LOCATION was 0xf47ff400 and the log showed no GPU
errors.

Finally, I reloaded amdgpu after a suspend, twice, with modprobe -r
and modprobe.  Each time amdgpu logged "PCI CONFIG reset" and "GPU
posting now..." during the reload, VRAM was at 0xF400000000 and
MC_VM_FB_LOCATION read 0xf47ff400.  VRAM is no longer at 0 by then, so
I think the reset came from the existing SMC check: with amdgpu
unloaded, SMC_SYSCON_CLOCK_CNTL_0 read 0x01000000 and SMC_PC_C was
about 0x205xx and changing (read through the MMIO BAR).  After the
second reload I logged in again and ran glxgears for a minute without
errors.

Tested-by: Francisco Beltrán Millalén <fbeltranmillalen@gmail.com> # MacBookPro14,3

Thanks again,
Francisco

Re: [PATCH v2 3/3] drm/amdgpu: reset VI ASIC on Apple boards with VRAM at 0

[Alex Deucher]

On Thu, Oct 15, 2026 at 9:26 AM Alex Deucher <alexdeucher@gmail.com> wrote:
>
> On Thu, Oct 15, 2026 at 9:06 AM Maciej Kucharek <qchcio@gmail.com> wrote:
> >
> > On MacBookPros with switchable graphics, the firmware puts VRAM at MC
> > address 0 when the iGPU is enabled.  A later post (S3 resume, GPU
> > reset) moves VRAM back to the VBIOS default.  gmc_v8_0 reads
> > MC_VM_FB_LOCATION once at init and reprograms it only on SR-IOV.  On
> > bare metal, the driver then keeps using the old layout.
> >
> > vi_reset_quirks[] handles this for the MacBookPro14,3 by PCI ID:
> >
> >   commit a22e5e4f2ebb ("drm/amdgpu: reset VI ASIC on MacBookPro14,3")
> >
> > Add the test that SI and CIK use: an Apple subsystem vendor and VRAM at
> > 0.  Other Polaris MacBookPros then get the same reset at load, for
> > example the MacBookPro13,3 if its firmware leaves VRAM at 0.  These
> > boards are not tested.
> >
> > Keep vi_reset_quirks[].  Its MacBookPro15,1 entries fix a different
> > failure, a module reload after S3:
> >
> >   commit a5be7ad8f5f0 ("drm/amdgpu: reset VI ASIC on MacBookPro15,1")
> >
> > VRAM is not at 0 at that point, so the new test may not cover it.
> >
> > After the reset, FB_BASE is not 0, so the new test does not fire again
> > on a module reload.
> >
> > Only compile-tested.
> >
> > Suggested-by: Alex Deucher <alexander.deucher@amd.com>
> > Cc: stable@vger.kernel.org
> > Assisted-by: Claude:claude-opus-5-5
> > Signed-off-by: Maciej Kucharek <qchcio@gmail.com>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/vi.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
> > index a0435fd55..cad6bbfce 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/vi.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/vi.c
> > @@ -1405,6 +1405,16 @@ static bool vi_need_reset_on_init(struct amdgpu_device *adev)
> >         unsigned int i;
> >         u32 clock_cntl, pc;
> >
> > +       /*
> > +        * MacBookPros with switchable graphics put VRAM at 0 when the iGPU
> > +        * is enabled.  Any later post (S3 resume, GPU reset) moves it back to
> > +        * the vbios default, so reset and post on load to start with the
> > +        * vbios layout.
> > +        */
> > +       if (adev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE &&
> > +           !(RREG32(mmMC_VM_FB_LOCATION) & MC_VM_FB_LOCATION__FB_BASE_MASK))
> > +               return true;
> > +
> >         for (i = 0; i < ARRAY_SIZE(vi_reset_quirks); i++)
> >                 if (adev->pdev->device == vi_reset_quirks[i].device &&
> >                     adev->pdev->subsystem_vendor == vi_reset_quirks[i].subsystem_vendor &&
>
> Please drop the now duplicate quirk handling here.

After re-reading your commit message and thinking about it more, I've
decided to take v1.  Series is:
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
and applied.

Thanks!

Alex

>
> Thanks,
>
> Alex
>
> > --
> > 2.55.0
> >

Re: [PATCH v2 3/3] drm/amdgpu: reset VI ASIC on Apple boards with VRAM at 0

[Sergey Armodin]

Hi Maciej,

I tested this patch on a MacBookPro14,3 with the Radeon Pro 560
(1002:67ef, subsystem 106b:0179, rev c0), which is not in
vi_reset_quirks[].  The kernel is 7.2.5 with commits a5be7ad8f5f0 and
a22e5e4f2ebb backported, plus distribution patches; amdgpu was built
from that tree with this patch on top.

Without the patch this board boots with VRAM at 0 every time
(MC_VM_FB_LOCATION 0x00ff0000), and a re-post moves it to 0xf4fff400
under the driver.

With it, after both a warm reboot and a cold boot (powered off for
three minutes), amdgpu logs "PCI CONFIG reset" and "GPU posting now..."
on load, VRAM is at 0x000000F400000000, MC_VM_FB_LOCATION reads
0xf4fff400 through debugfs, and there are no amdgpu errors.

I then ran five S3 cycles with rtcwake.  After each resume
MC_VM_FB_LOCATION was still 0xf4fff400, the GART table was at
0x000000F401B00000, the internal panel came back, and the kernel log
showed no amdgpu errors, ring timeouts or IOMMU faults.

The 560 is not in vi_reset_quirks[], so v3 3/3 behaves the same way on
this machine.  This also covers the one-line quirk entry I sent for
this GPU [1], so that one can be dropped.

Tested-by: Sergey Armodin <dolph-in@yandex.ru> # MacBookPro14,3, Radeon Pro 560

[1] https://lore.kernel.org/amd-gfx/20261016-amdgpu-pro560-quirk-v1-1-3e5d3fe5ff29@yandex.ru/