Hi Fabio
On 2021-09-14 10:48, Fabio Estevam wrote:
Since commit 98659487b845 ("drm/msm: add support to take dpu snapshot")
the following NULL pointer dereference is seen on i.MX53:
[ 3.275493] msm msm: bound 30000000.gpu (ops a3xx_ops)
[ 3.287174] [drm] Initialized msm 1.8.0 20130625 for msm on minor 0
[ 3.293915] 8<--- cut here ---
[ 3.297012] Unable to handle kernel NULL pointer dereference at
virtual address 00000028
[ 3.305244] pgd = (ptrval)
[ 3.307989] [00000028] *pgd=00000000
[ 3.311624] Internal error: Oops: 805 [#1] SMP ARM
[ 3.316430] Modules linked in:
[ 3.319503] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.14.0+g682d702b426b #1
[ 3.326652] Hardware name: Freescale i.MX53 (Device Tree Support)
[ 3.332754] PC is at __mutex_init+0x14/0x54
[ 3.336969] LR is at msm_disp_snapshot_init+0x24/0xa0
i.MX53 does not use the DPU controller.
Fix the problem by only calling msm_disp_snapshot_init() on platforms
that
use the DPU controller.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot")
Signed-off-by: Fabio Estevam <festevam@xxxxxxxxx>
---
drivers/gpu/drm/msm/msm_drv.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_drv.c
b/drivers/gpu/drm/msm/msm_drv.c
index 2e6fc185e54d..2aa2266454b7 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -630,10 +630,11 @@ static int msm_drm_init(struct device *dev,
const struct drm_driver *drv)
if (ret)
goto err_msm_uninit;
- ret = msm_disp_snapshot_init(ddev);
- if (ret)
- DRM_DEV_ERROR(dev, "msm_disp_snapshot_init failed ret = %d\n", ret);
-
+ if (kms) {
+ ret = msm_disp_snapshot_init(ddev);
+ if (ret)
+ DRM_DEV_ERROR(dev, "msm_disp_snapshot_init failed ret = %d\n",
ret);
+ }
Are you not using DPU or are you not using mdp4/mdp5 as well? Even if
you are using any of mdps, kms should
not be NULL. Hence wanted to check the test case.
drm_mode_config_reset(ddev);
#ifdef CONFIG_DRM_FBDEV_EMULATION
