[PATCH] drm/amd/display: Temporarily disable hostvm on DCN31

[PATCH] drm/amd/display: Temporarily disable hostvm on DCN31

[Alex Deucher]

From: Aurabindo Pillai <aurabindo.pillai@amd.com>

With HostVM enabled, DCN31 fails to pass validation for 3x4k60. Some Linux
userspace does not downgrade one of the monitors to 4k30, and the result
is that the monitor does not light up. Disable it until the bandwidth
calculation failure is resolved.

Reviewed-by: Sun peng Li <sunpeng.li@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit ba93dddfc92084a1e28ea447ec4f8315f3d8d3fd)
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c
index 911bd60d4fbc..3c42ba8566cf 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c
@@ -890,7 +890,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.disable_z10 = true,
 	.enable_legacy_fast_update = true,
 	.enable_z9_disable_interface = true, /* Allow support for the PMFW interface for disable Z9*/
-	.dml_hostvm_override = DML_HOSTVM_NO_OVERRIDE,
+	.dml_hostvm_override = DML_HOSTVM_OVERRIDE_FALSE,
 	.using_dml2 = false,
 };
 
-- 
2.49.0

Re: [PATCH] drm/amd/display: Temporarily disable hostvm on DCN31

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: ba93dddfc92084a1e28ea447ec4f8315f3d8d3fd

WARNING: Author mismatch between patch and found commit:
Backport author: Alex Deucher<alexander.deucher@amd.com>
Commit author: Aurabindo Pillai<aurabindo.pillai@amd.com>

Note: The patch differs from the upstream commit:
---
1:  ba93dddfc9208 ! 1:  5e9fb61f1028c drm/amd/display: Temporarily disable hostvm on DCN31
    @@ Commit message
         Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
         Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
         Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
    +    (cherry picked from commit ba93dddfc92084a1e28ea447ec4f8315f3d8d3fd)
    +    Cc: stable@vger.kernel.org
     
      ## drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c ##
     @@ drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c: static const struct dc_debug_options debug_defaults_drv = {
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.14.y       |  Success    |  Success   |
| stable/linux-6.13.y       |  Success    |  Success   |
| stable/linux-6.12.y       |  Success    |  Success   |
| stable/linux-6.6.y        |  Success    |  Success   |
| stable/linux-6.1.y        |  Success    |  Success   |
| stable/linux-5.15.y       |  Success    |  Success   |
| stable/linux-5.10.y       |  Success    |  Success   |
| stable/linux-5.4.y        |  Success    |  Success   |

Re: [PATCH] drm/amd/display: Temporarily disable hostvm on DCN31

[Greg KH]

On Mon, Apr 07, 2025 at 07:43:29PM -0400, Alex Deucher wrote:
> From: Aurabindo Pillai <aurabindo.pillai@amd.com>
> 
> With HostVM enabled, DCN31 fails to pass validation for 3x4k60. Some Linux
> userspace does not downgrade one of the monitors to 4k30, and the result
> is that the monitor does not light up. Disable it until the bandwidth
> calculation failure is resolved.
> 
> Reviewed-by: Sun peng Li <sunpeng.li@amd.com>
> Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
> Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> (cherry picked from commit ba93dddfc92084a1e28ea447ec4f8315f3d8d3fd)
> Cc: stable@vger.kernel.org
> ---
>  drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

What tree(s) is this for?

RE: [PATCH] drm/amd/display: Temporarily disable hostvm on DCN31

[Deucher, Alexander]

[Public]

> -----Original Message-----
> From: Greg KH <gregkh@linuxfoundation.org>
> Sent: Tuesday, April 8, 2025 2:45 AM
> To: Deucher, Alexander <Alexander.Deucher@amd.com>
> Cc: stable@vger.kernel.org; sashal@kernel.org; Pillai, Aurabindo
> <Aurabindo.Pillai@amd.com>; Li, Sun peng (Leo) <Sunpeng.Li@amd.com>;
> Mohamed, Zaeem <Zaeem.Mohamed@amd.com>; Wheeler, Daniel
> <Daniel.Wheeler@amd.com>
> Subject: Re: [PATCH] drm/amd/display: Temporarily disable hostvm on DCN31
>
> On Mon, Apr 07, 2025 at 07:43:29PM -0400, Alex Deucher wrote:
> > From: Aurabindo Pillai <aurabindo.pillai@amd.com>
> >
> > With HostVM enabled, DCN31 fails to pass validation for 3x4k60. Some
> > Linux userspace does not downgrade one of the monitors to 4k30, and
> > the result is that the monitor does not light up. Disable it until the
> > bandwidth calculation failure is resolved.
> >
> > Reviewed-by: Sun peng Li <sunpeng.li@amd.com>
> > Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
> > Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
> > Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
> > Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked
> > from commit ba93dddfc92084a1e28ea447ec4f8315f3d8d3fd)
> > Cc: stable@vger.kernel.org
> > ---
> >  drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
>
> What tree(s) is this for?

6.10 and newer.

Thanks,

Alex