Re: [PATCH v2] drm/amd/display: invalidate DP CEC state on s3 suspend

[Mario Limonciello <mario.limonciello@amd.com>]

On 9/14/26 21:27, Dan Himebauch wrote:
> Amended and added issue link, thanks!
> 
>  From 2916fc883b80cf106ba2b06d8dadbdae45eff7db Mon Sep 17 00:00:00 2001
> From: Daniel Kurt Himebauch <danielhimebauch@gmail.com>
> Date: Fri, 11 Sep 2026 21:11:10 -0400
> Subject: [PATCH v2] drm/amd/display: invalidate DP CEC state on s3 suspend
> 
> Some Linux HTPCs with discrete GPUs use active DisplayPort-to-HDMI
> adapters to carry CEC over DP AUX. This provides a CEC path on systems
> where the GPU does not expose native HDMI CEC.
> 
> During S3 suspend, amdgpu invalidates native HDMI CEC state but leaves
> the DP AUX CEC physical address valid. The adapter can retain stale CEC
> state across suspend, causing transmissions during resume to fail before
> the adapter is reconfigured.
> 
> For AUX-mode connectors, invalidate the DP AUX CEC physical address
> during suspend. Normal connector detection on resume then reattaches the
> adapter using the EDID-derived physical address.
> 
> Tested on a Radeon RX 9070 XT HTPC running SteamOS with a UGREEN
> DP-to-HDMI adapter on amd-staging-drm-next at commit d8ab7636160e
> ("drm/amd/amdgpu: remove duplicated code in gfx_v11 and gfx_v12").
> The unmodified tree reproduced resume NACKs. With this change, multiple
> cycles showed Image View On and Active Source transmissions.
> 
> Link: https://gitlab.steamos.cloud/holo/linux-cec/-/issues/5
> Assisted-by: Codex:GPT-5.6-Luna
> Signed-off-by: Daniel Kurt Himebauch <danielhimebauch@gmail.com>
> 
> ---
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c    | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> index 0b446133edd8..919394778a25 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
> @@ -372,10 +372,13 @@ void amdgpu_dm_s3_handle_hdmi_cec(struct
> drm_device *ddev, bool suspend)
>    continue;
> 
>    aconnector = to_amdgpu_dm_connector(connector);
> - if (suspend)
> + if (suspend) {
>    hdmi_cec_unset_edid(aconnector);
> - else
> + if (aconnector->dc_link && aconnector->dc_link->aux_mode)
> + drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux);
> + } else {
>    amdgpu_dm_hdmi_cec_set_edid(aconnector);
> + }
>    }
>    drm_connector_list_iter_end(&conn_iter);
>   }

Something is wrong with your whitespace.  Can you send using git 
send-email perhaps?

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---
   ✓ [PATCH v2] drm/amd/display: invalidate DP CEC state on s3 suspend
   ---
   ✓ Signed: DKIM/gmail.com
---
Total patches: 1
---
Applying: drm/amd/display: invalidate DP CEC state on s3 suspend
Patch failed at 0001 drm/amd/display: invalidate DP CEC state on s3 suspend
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
error: git diff header lacks filename information when removing 1 
leading pathname component (line 6)
hint: Use 'git am --show-current-patch=diff' to see the failed patch

╰─❯ git am --show-current-patch=diff > patch
╰─❯ patch -p1 < patch 
  
  

patching file drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
patch: **** malformed patch at line 11: drm_device *ddev, bool suspend)