Re: [PATCH] drm/i915/dp: remove redundant link state check

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Removing the DP link state check from `intel_dp_detect()` breaks recovery for monitors that drop link synchronization silently (without sending an HPD IRQ).
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commit 26b9e2acc7df07dcc2e2026421a5c54d7a72b52e
Author: tarun-tarun143 <tarund18303@gmail.com>

drm/i915/dp: remove redundant link state check

This commit removes the DP link state check from intel_dp_detect(), relying
instead on the link recovery paths after modesets and hotplug events.

> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 113d767e62e9c..ffd39206b958e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -6379,18 +6379,6 @@ intel_dp_detect(struct drm_connector *_connector,
>  		status = connector_status_disconnected;
>  		goto out_unset_edid;
>  	}
> -
> -	/*
> -	 * Some external monitors do not signal loss of link synchronization
> -	 * with an IRQ_HPD, so force a link status check.
> -	 *
> -	 * TODO: this probably became redundant, so remove it: the link state
> -	 * is rechecked/recovered now after modesets, where the loss of
> -	 * synchronization tends to occur.
> -	 */
> -	if (!intel_dp_is_edp(intel_dp))
> -		intel_dp_check_link_state(intel_dp);
> -

[Severity: Medium]
Does removing this check break recovery for monitors that drop link
synchronization silently?

While the link state is recovered after modesets and hotplug events, some
non-compliant monitors fail to assert an HPD IRQ when the main link drops
due to issues like EMI. When this hardware failure happens, a user or
desktop environment running a probe calls intel_dp_detect().

Before this patch, intel_dp_detect() would read the DPCD link status and
queue a link retrain, acting as a manual fallback. By removing this check,
intel_dp_detect() succeeds via the independent AUX channel but ignores the
broken main link. Will this leave users with a permanent blank screen until
a full modeset or physical replug is performed?

>  	/*
>  	 * Clearing NACK and defer counts to get their exact values
>  	 * while reading EDID which are required by Compliance tests

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Sashiko AI review · https://sashiko.dev/#/patchset/20260826044533.9292-1-tarund18303@gmail.com?part=1