Re: [PATCH 1/2] drm/msm/mdp4: keep the bus clock enabled while a CRTC is active

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 6/11/26 8:07 AM, Alexandre MINETTE via B4 Relay wrote:
> From: Alexandre MINETTE <contact@alex-min.fr>
> 
> MDP4 scanout continues to fetch framebuffer data while the CRTC is
> active. Keep the AXI/bus clock enabled for the lifetime of each active
> CRTC so that temporary MDP4 disable paths do not gate the bus clock
> while scanout is still running.
> 
> This avoids display corruption seen on the Samsung Galaxy S4 when the
> display pipeline is active.
> 
> Signed-off-by: Alexandre MINETTE <contact@alex-min.fr>
> ---

[...]

> +void mdp4_crtc_bus_put(struct mdp4_kms *mdp4_kms)
> +{
> +	mutex_lock(&mdp4_kms->clock_lock);

If you use guard(mutex)(&mdp4_kms->lock_lock), you can drop
the manual _unlock() calls (the lock will be dropped once you
exit the scope

Konrad