[PATCH v2 1/2] drm/msm: Call shutdown conditionally

[Fabio Estevam]

Gentle ping...

On Fri, Jan 29, 2021 at 8:09 AM Fabio Estevam <festevam at gmail.com> wrote:
>
> Hi Rob,
>
> Any comments on this series, please?
>
> On Tue, Jan 19, 2021 at 8:15 PM Fabio Estevam <festevam at 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 at vger.kernel.org>
> > Fixes: 9d5cbf5fe46e ("drm/msm: add shutdown support for display platform_driver")
> > Suggested-by: Rob Clark <robdclark at gmail.com>
> > Signed-off-by: Fabio Estevam <festevam at 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
> >