[PATCH v2] drm/msm/dpu: handle pm_runtime_get_sync() errors in bind path

From: Abhinav Kumar <quic_abhinavk@quicinc.com>
To: <freedreno@lists.freedesktop.org>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>,
	dri-devel@lists.freedesktop.org, swboyd@chromium.org,
	seanpaul@chromium.org, dmitry.baryshkov@linaro.org,
	quic_jesszhan@quicinc.com, quic_aravindh@quicinc.com,
	quic_khsieh@quicinc.com
Subject: [PATCH v2] drm/msm/dpu: handle pm_runtime_get_sync() errors in bind path
Date: Wed, 18 May 2022 15:34:07 -0700	[thread overview]
Message-ID: <20220518223407.26147-1-quic_abhinavk@quicinc.com> (raw)

If there are errors while trying to enable the pm in the
bind path, it will lead to unclocked access of hw revision
register thereby crashing the device.

This will not address why the pm_runtime_get_sync() fails
but at the very least we should be able to prevent the
crash by handling the error and bailing out earlier.

changes in v2:
	- use pm_runtime_resume_and_get() instead of
	  pm_runtime_get_sync()

Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index 2b9d931474e0..bce47647d891 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -1089,7 +1089,9 @@ static int dpu_kms_hw_init(struct msm_kms *kms)
 
 	dpu_kms_parse_data_bus_icc_path(dpu_kms);
 
-	pm_runtime_get_sync(&dpu_kms->pdev->dev);
+	rc = pm_runtime_resume_and_get(&dpu_kms->pdev->dev);
+	if (rc < 0)
+		goto error;
 
 	dpu_kms->core_rev = readl_relaxed(dpu_kms->mmio + 0x0);
 
-- 
2.35.1

