]> www.infradead.org Git - users/jedix/linux-maple.git/commit
drm/exynos: exynos7_drm_decon: add vblank check in IRQ handling
authorKaustabh Chakraborty <kauschluss@disroot.org>
Thu, 26 Jun 2025 19:20:30 +0000 (00:50 +0530)
committerInki Dae <inki.dae@samsung.com>
Sun, 29 Jun 2025 07:58:16 +0000 (16:58 +0900)
commitb846350aa272de99bf6fecfa6b08e64ebfb13173
tree19641e42545f790c48c3f557afbf6e1adb52b09f
parent18665eaa2acbe17da11c2748ac43c2f4ec2fad85
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>
drivers/gpu/drm/exynos/exynos7_drm_decon.c