Re: [PATCH] drm/msm: Fix shutdown

From: Abhinav Kumar
Date: Wed May 04 2022 - 19:49:47 EST




On 5/4/2022 3:49 PM, Douglas Anderson wrote:
When rebooting on my sc7280-herobrine based device, I got a
crash. Upon debugging, I found that I was in msm_drv_shutdown() and my
"pdev" was the one associated with mdss_probe().

From source, I found that mdss_probe() has the line:
platform_set_drvdata(pdev, mdss);
...where "mdss" is of type "struct msm_mdss *".

Also from source, I saw that in msm_drv_shutdown() we have the line:
struct msm_drm_private *priv = platform_get_drvdata(pdev);

This is a mismatch and is the root of the problem.

Further digging made it apparent that msm_drv_shutdown() is only
supposed to be used for parts of the msm display framework that also
call msm_drv_probe() but mdss_probe() doesn't call
msm_drv_probe(). Let's remove the shutdown functon from msm_mdss.c.

Digging a little further, code inspection found that two drivers that
use msm_drv_probe() weren't calling msm_drv_shutdown(). Let's add it
to them.

Fixes: ecb23f2e3009 ("drm/msm: split the main platform driver")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Makes sense to me, and issue should happen everytime we shutdown so not sure how it didnt hit?

---

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 1 +
drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 1 +
drivers/gpu/drm/msm/msm_mdss.c | 1 -
3 files changed, 2 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 143d6643be53..2b9d931474e0 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -1350,6 +1350,7 @@ MODULE_DEVICE_TABLE(of, dpu_dt_match);
static struct platform_driver dpu_driver = {
.probe = dpu_dev_probe,
.remove = dpu_dev_remove,
+ .shutdown = msm_drv_shutdown,
.driver = {
.name = "msm_dpu",
.of_match_table = dpu_dt_match,
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
index 9b7bbc3adb97..3d5621a68f85 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
@@ -1009,6 +1009,7 @@ MODULE_DEVICE_TABLE(of, mdp5_dt_match);
static struct platform_driver mdp5_driver = {
.probe = mdp5_dev_probe,
.remove = mdp5_dev_remove,
+ .shutdown = msm_drv_shutdown,
.driver = {
.name = "msm_mdp",
.of_match_table = mdp5_dt_match,
diff --git a/drivers/gpu/drm/msm/msm_mdss.c b/drivers/gpu/drm/msm/msm_mdss.c
index 20f154dda9cf..0454a571adf7 100644
--- a/drivers/gpu/drm/msm/msm_mdss.c
+++ b/drivers/gpu/drm/msm/msm_mdss.c
@@ -397,7 +397,6 @@ MODULE_DEVICE_TABLE(of, mdss_dt_match);
static struct platform_driver mdss_platform_driver = {
.probe = mdss_probe,
.remove = mdss_remove,
- .shutdown = msm_drv_shutdown,

Question to doug/dmitry:

Now that we removed msm_drv_shutdown, perhaps we should have a mdss_shutdown instead and call msm_mdss_destroy() internally?

.driver = {
.name = "msm-mdss",
.of_match_table = mdss_dt_match,