[PATCH] drm/amd/display: Look at firmware version to determine using dmub on dcn21

[PATCH] drm/amd/display: Look at firmware version to determine using dmub on dcn21

[Mario Limonciello]

Newer DMUB firmware on Renoir and Green Sardine do not need to disable dmcu
and this actually causes problems with DP-C alt mode for a number of machines.

Backport the fix from this from mainline.  It's a hand modified backport because
mainline switched to IP version checking which doesn't exist in linux-stable.

BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1772
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1735
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
Resend, also pick up Alex's tag from last submission
This was previously sent to stable@kernel.org not stable@vger.kernel.org.

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 1ea31dcc7a8b..084491afe540 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1141,8 +1141,15 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 	case CHIP_RAVEN:
 	case CHIP_RENOIR:
 		init_data.flags.gpu_vm_support = true;
-		if (ASICREV_IS_GREEN_SARDINE(adev->external_rev_id))
+		switch (adev->dm.dmcub_fw_version) {
+		case 0: /* development */
+		case 0x1: /* linux-firmware.git hash 6d9f399 */
+		case 0x01000000: /* linux-firmware.git hash 9a0b0f4 */
+			init_data.flags.disable_dmcu = false;
+			break;
+		default:
 			init_data.flags.disable_dmcu = true;
+		}
 		break;
 	case CHIP_VANGOGH:
 	case CHIP_YELLOW_CARP:
-- 
2.25.1

Re: [PATCH] drm/amd/display: Look at firmware version to determine using dmub on dcn21

[Greg KH]

On Wed, Nov 10, 2021 at 05:25:54PM -0600, Mario Limonciello wrote:
> Newer DMUB firmware on Renoir and Green Sardine do not need to disable dmcu
> and this actually causes problems with DP-C alt mode for a number of machines.
> 
> Backport the fix from this from mainline.  It's a hand modified backport because
> mainline switched to IP version checking which doesn't exist in linux-stable.
> 
> BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1772
> BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1735
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
> ---
> Resend, also pick up Alex's tag from last submission
> This was previously sent to stable@kernel.org not stable@vger.kernel.org.
>


<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>