From 682f99b8ae886c22ba9f16df454aecc8c6d803ba Mon Sep 17 00:00:00 2001 From: "maxime@cerno.tech" Date: Mon, 24 Oct 2022 11:36:33 +0200 Subject: 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: 6bed2ea3cb38 ("drm/vc4: hdmi: Reset link on hotplug") Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20221024093634.118190-1-maxime@cerno.tech Signed-off-by: Maxime Ripard --- drivers/gpu/drm/vc4/vc4_hdmi.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 596e311d6e58..9e549fa07467 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -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 -- cgit v1.2.3-59-g8ed1b