Gentle ping...

On Fri, Jan 29, 2021 at 8:09 AM Fabio Estevam festevam@gmail.com wrote:

Hi Rob,

Any comments on this series, please?

On Tue, Jan 19, 2021 at 8:15 PM Fabio Estevam festevam@gmail.com wrote:

...

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@vger.kernel.org Fixes: 9d5cbf5fe46e ("drm/msm: add shutdown support for display platform_driver") Suggested-by: Rob Clark robdclark@gmail.com Signed-off-by: Fabio Estevam festevam@gmail.com

---

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