Issuing a 'reboot' command in i.MX5 leads to the following flow:
[ 24.557742] [<c0769b78>] (msm_atomic_commit_tail) from [<c06db0b4>]
(commit_tail+0xa4/0x1b0)
[ 24.566349] [<c06db0b4>] (commit_tail) from [<c06dbed0>]
(drm_atomic_helper_commit+0x154/0x188)
[ 24.575193] [<c06dbed0>] (drm_atomic_helper_commit) from
[<c06db604>] (drm_atomic_helper_disable_all+0x154/0x1c0)
[ 24.585599] [<c06db604>] (drm_atomic_helper_disable_all) from
[<c06db704>] (drm_atomic_helper_shutdown+0x94/0x12c)
[ 24.596094] [<c06db704>] (drm_atomic_helper_shutdown) from
In the i.MX5 case, priv->kms is not populated (as i.MX5 does not use any
of the Qualcomm display controllers), causing a NULL pointer
dereference in msm_atomic_commit_tail():
[ 24.268964] 8<--- cut here ---
[ 24.274602] Unable to handle kernel NULL pointer dereference at
virtual address 00000000
[ 24.283434] pgd = (ptrval)
[ 24.286387] [00000000] *pgd=ca212831
[ 24.290788] Internal error: Oops: 17 [#1] SMP ARM
[ 24.295609] Modules linked in:
[ 24.298777] CPU: 0 PID: 197 Comm: init Not tainted 5.11.0-rc2-next-20210111 #333
[ 24.306276] Hardware name: Freescale i.MX53 (Device Tree Support)
[ 24.312442] PC is at msm_atomic_commit_tail+0x54/0xb9c
[ 24.317743] LR is at commit_tail+0xa4/0x1b0
Fix the problem by calling drm_atomic_helper_shutdown() conditionally.
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 9d5cbf5fe46e ("drm/msm: add shutdown support for display platform_driver")
Suggested-by: Rob Clark <robdclark@xxxxxxxxx>
Signed-off-by: Fabio Estevam <festevam@xxxxxxxxx>
---
Changes since v1:
- Explain in the commit log that the problem happens after a 'reboot' command.
drivers/gpu/drm/msm/msm_drv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 108c405e03dd..c082b72b9e3b 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -1311,7 +1311,8 @@ static void msm_pdev_shutdown(struct platform_device *pdev)
{
struct drm_device *drm = platform_get_drvdata(pdev);
- drm_atomic_helper_shutdown(drm);
+ if (get_mdp_ver(pdev))
+ drm_atomic_helper_shutdown(drm);
}
static const struct of_device_id dt_match[] = {
--
2.25.1
