drm/meson: fix shutdown crash when component not probed
authorNeil Armstrong <narmstrong@baylibre.com>
Fri, 30 Apr 2021 08:27:44 +0000 (10:27 +0200)
committerNeil Armstrong <narmstrong@baylibre.com>
Tue, 25 May 2021 07:22:27 +0000 (09:22 +0200)
commit7cfc4ea78fc103ea51ecbacd9236abb5b1c490d2
tree712f8277efae7e39aca42bbc9e0193b54b18de94
parent7e008b02557ccece4d2c31fb0eaf6243cbc87121
drm/meson: fix shutdown crash when component not probed

When main component is not probed, by example when the dw-hdmi module is
not loaded yet or in probe defer, the following crash appears on shutdown:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
...
pc : meson_drv_shutdown+0x24/0x50
lr : platform_drv_shutdown+0x20/0x30
...
Call trace:
meson_drv_shutdown+0x24/0x50
platform_drv_shutdown+0x20/0x30
device_shutdown+0x158/0x360
kernel_restart_prepare+0x38/0x48
kernel_restart+0x18/0x68
__do_sys_reboot+0x224/0x250
__arm64_sys_reboot+0x24/0x30
...

Simply check if the priv struct has been allocated before using it.

Fixes: fa0c16caf3d7 ("drm: meson_drv add shutdown function")
Reported-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210430082744.3638743-1-narmstrong@baylibre.com
drivers/gpu/drm/meson/meson_drv.c