[PATCH 3/3] drm: hikey9xxx: Fix null pointer crash on reboot
From: John Stultz
Date: Wed Aug 19 2020 - 23:41:31 EST
This is against Mauro's tree here:
https://gitlab.freedesktop.org/mchehab_kernel/hikey-970/-/commits/master/
On reboot we see the following crash:
[ 608.746787] Unable to handle kernel read from unreadable memory at virtual address 00000000000000a8
...
[ 608.822101] CPU: 3 PID: 234 Comm: kworker/3:2 Not tainted 5.8.0-00183-g03481a190c60-dirty #32
[ 608.830626] Hardware name: HiKey960 (DT)
[ 608.834571] Workqueue: events drm_mode_rmfb_work_fn
[ 608.839454] pstate: 80400005 (Nzcv daif +PAN -UAO BTYPE=--)
[ 608.845031] pc : drm_gem_fb_get_obj+0x10/0x28
[ 608.849390] lr : drm_fb_cma_get_gem_obj+0x10/0x20
[ 608.854093] sp : ffffffc012f63b10
[ 608.857404] x29: ffffffc012f63b10 x28: ffffff8212282e00
[ 608.862716] x27: 0000000000000000 x26: ffffff8217501800
[ 608.868027] x25: 0000000000000000 x24: ffffffc012f63d60
[ 608.873339] x23: 0000000000000001 x22: ffffff8217504080
[ 608.878652] x21: ffffffc0119b9000 x20: ffffff8212282e00
[ 608.883963] x19: ffffff82175047c0 x18: ffffffffffffffff
[ 608.889275] x17: ffffff8219c97708 x16: ffffff8219c97728
[ 608.894586] x15: ffffffc0119b9d08 x14: 0000000000000000
[ 608.899898] x13: 0000000000000000 x12: 0000000000000000
[ 608.905209] x11: 0000003c00000000 x10: 0000046500000441
[ 608.910519] x9 : ffffffc0119b9d08 x8 : ffffffc011bf7000
[ 608.915830] x7 : 0000000000000898 x6 : ffffff8217504080
[ 608.921142] x5 : ffffff8212282e00 x4 : ffffffc0111935e0
[ 608.926454] x3 : 0000000000000000 x2 : ffffffc0119b9d08
[ 608.931764] x1 : 0000000000000000 x0 : 0000000000000000
[ 608.937079] Call trace:
[ 608.939531] drm_gem_fb_get_obj+0x10/0x28
[ 608.943547] hisi_fb_pan_display+0x50/0x1f8
[ 608.947736] dss_plane_atomic_update+0x10/0x20
[ 608.952183] drm_atomic_helper_commit_planes+0xe0/0x228
[ 608.957412] drm_atomic_helper_commit_tail+0x34/0x80
[ 608.962377] commit_tail+0x150/0x180
[ 608.965955] drm_atomic_helper_commit+0x164/0x178
[ 608.970665] drm_atomic_commit+0x4c/0x60
[ 608.974591] drm_framebuffer_remove+0x3f4/0x440
[ 608.979123] drm_mode_rmfb_work_fn+0x48/0x68
[ 608.983398] process_one_work+0x1ec/0x4b0
[ 608.987408] worker_thread+0x208/0x478
[ 608.991160] kthread+0x140/0x150
[ 608.994390] ret_from_fork+0x10/0x30
[ 608.997972] Code: d503233f 71000c3f 540000a8 8b214c01 (f9405420)
[ 609.004069] ---[ end trace a837c42fc434e1a4 ]---
Which is due to the plane->state->fb value being null.
Fix this with a solution used in a different version of this
patch series.
Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Cc: dri-devel <dri-devel@xxxxxxxxxxxxxxxxxxxxx>
Cc: Liwei Cai <cailiwei@xxxxxxxxxxxxx>
Cc: Xinliang Liu <xinliang.liu@xxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Chen Feng <puck.chen@xxxxxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/staging/hikey9xx/gpu/kirin9xx_drm_dss.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/staging/hikey9xx/gpu/kirin9xx_drm_dss.c b/drivers/staging/hikey9xx/gpu/kirin9xx_drm_dss.c
index f2e99c766927..7adbd924bec2 100644
--- a/drivers/staging/hikey9xx/gpu/kirin9xx_drm_dss.c
+++ b/drivers/staging/hikey9xx/gpu/kirin9xx_drm_dss.c
@@ -702,6 +702,13 @@ static int dss_plane_atomic_check(struct drm_plane *plane,
static void dss_plane_atomic_update(struct drm_plane *plane,
struct drm_plane_state *old_state)
{
+ struct drm_plane_state *state = plane->state;
+
+ if (!state->fb) {
+ state->visible = false;
+ return;
+ }
+
hisi_fb_pan_display(plane);
}
--
2.17.1