diff options
| author | Kaustabh Chakraborty <kauschluss@disroot.org> | 2025-06-27 00:50:30 +0530 |
|---|---|---|
| committer | Inki Dae <inki.dae@samsung.com> | 2025-06-29 16:58:16 +0900 |
| commit | b846350aa272de99bf6fecfa6b08e64ebfb13173 (patch) | |
| tree | 19641e42545f790c48c3f557afbf6e1adb52b09f | |
| parent | 18665eaa2acbe17da11c2748ac43c2f4ec2fad85 (diff) | |
drm/exynos: exynos7_drm_decon: add vblank check in IRQ handling
If there's support for another console device (such as a TTY serial),
the kernel occasionally panics during boot. The panic message and a
relevant snippet of the call stack is as follows:
Unable to handle kernel NULL pointer dereference at virtual address 000000000000000
Call trace:
drm_crtc_handle_vblank+0x10/0x30 (P)
decon_irq_handler+0x88/0xb4
[...]
Otherwise, the panics don't happen. This indicates that it's some sort
of race condition.
Add a check to validate if the drm device can handle vblanks before
calling drm_crtc_handle_vblank() to avoid this.
Cc: stable@vger.kernel.org
Fixes: 96976c3d9aff ("drm/exynos: Add DECON driver")
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
| -rw-r--r-- | drivers/gpu/drm/exynos/exynos7_drm_decon.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/exynos/exynos7_drm_decon.c b/drivers/gpu/drm/exynos/exynos7_drm_decon.c index f91daefa9d2b..805aa28c1723 100644 --- a/drivers/gpu/drm/exynos/exynos7_drm_decon.c +++ b/drivers/gpu/drm/exynos/exynos7_drm_decon.c @@ -636,6 +636,10 @@ static irqreturn_t decon_irq_handler(int irq, void *dev_id) if (!ctx->drm_dev) goto out; + /* check if crtc and vblank have been initialized properly */ + if (!drm_dev_has_vblank(ctx->drm_dev)) + goto out; + if (!ctx->i80_if) { drm_crtc_handle_vblank(&ctx->crtc->base); |