Unverified Commit 682f99b8 authored by maxime@cerno.tech's avatar maxime@cerno.tech Committed by Maxime Ripard
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drm/vc4: hdmi: Take our lock to reset the link 



We access some fields protected by our internal mutex in
vc4_hdmi_reset_link() (saved_adjusted_mode, output_bpc, output_format)
and are calling functions that need to have that lock taken
(vc4_hdmi_supports_scrambling()).

However, the current code doesn't lock that mutex. Let's make sure it
does.

Fixes: 6bed2ea3 ("drm/vc4: hdmi: Reset link on hotplug")
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20221024093634.118190-1-maxime@cerno.tech


Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
parent fc007fb8

drivers/gpu/drm/vc4/vc4_hdmi.c

+17 −4
Original line number Diff line number Diff line
@@ -349,27 +349,40 @@ static int vc4_hdmi_reset_link(struct drm_connector *connector, 
	if (!crtc_state->active)

		return 0;



	if (!vc4_hdmi_supports_scrambling(encoder))

	mutex_lock(&vc4_hdmi->mutex);



	if (!vc4_hdmi_supports_scrambling(encoder)) {

		mutex_unlock(&vc4_hdmi->mutex);

		return 0;

	}



	scrambling_needed = vc4_hdmi_mode_needs_scrambling(&vc4_hdmi->saved_adjusted_mode,

							   vc4_hdmi->output_bpc,

							   vc4_hdmi->output_format);

	if (!scrambling_needed)

	if (!scrambling_needed) {

		mutex_unlock(&vc4_hdmi->mutex);

		return 0;

	}



	if (conn_state->commit &&

	    !try_wait_for_completion(&conn_state->commit->hw_done))

	    !try_wait_for_completion(&conn_state->commit->hw_done)) {

		mutex_unlock(&vc4_hdmi->mutex);

		return 0;

	}



	ret = drm_scdc_readb(connector->ddc, SCDC_TMDS_CONFIG, &config);

	if (ret < 0) {

		drm_err(drm, "Failed to read TMDS config: %d\n", ret);

		mutex_unlock(&vc4_hdmi->mutex);

		return 0;

	}



	if (!!(config & SCDC_SCRAMBLING_ENABLE) == scrambling_needed)

	if (!!(config & SCDC_SCRAMBLING_ENABLE) == scrambling_needed) {

		mutex_unlock(&vc4_hdmi->mutex);

		return 0;

	}



	mutex_unlock(&vc4_hdmi->mutex);



	/*

	 * HDMI 2.0 says that one should not send scrambled data