[PATCH] drm/msm/dp: fix runtime_pm handling in dp_wait_hpd_asserted

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
	Abhinav Kumar <quic_abhinavk@quicinc.com>,
	Kuogee Hsieh <quic_khsieh@quicinc.com>,
	Sankeerth Billakanti <quic_sbillaka@quicinc.com>
Cc: Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Stephen Boyd <swboyd@chromium.org>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
	freedreno@lists.freedesktop.org
Subject: [PATCH] drm/msm/dp: fix runtime_pm handling in dp_wait_hpd_asserted
Date: Tue, 27 Feb 2024 00:34:45 +0200	[thread overview]
Message-ID: <20240226223446.4194079-1-dmitry.baryshkov@linaro.org> (raw)

The function dp_wait_hpd_asserted() uses pm_runtime_get_sync() and
doesn't care about the return value. Potentially this can lead to
unclocked access if for some reason resuming of the DP controller fails.

Change the function to use pm_runtime_resume_and_get() and return an
error if resume fails.

Fixes: e2969ee30252 ("drm/msm/dp: move of_dp_aux_populate_bus() to eDP probe()")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/dp/dp_aux.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index 03f4951c49f4..1a264e7deb90 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -509,7 +509,10 @@ static int dp_wait_hpd_asserted(struct drm_dp_aux *dp_aux,
 
 	aux = container_of(dp_aux, struct dp_aux_private, dp_aux);
 
-	pm_runtime_get_sync(aux->dev);
+	ret = pm_runtime_resume_and_get(aux->dev);
+	if (ret)
+		return ret;
+
 	ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog);
 	pm_runtime_put_sync(aux->dev);
 
-- 
2.39.2

