On Sat, 16 Jul 2022 at 10:13, Zheyu Ma <zheyuma97@xxxxxxxxx> wrote: > > When removing the module we will get the following warning: > > [ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered > [ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI > [ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > [ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130 > [ 31.921825] Call Trace: > [ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw] > [ 31.923139] i2c_device_remove+0x181/0x1f0 > > The two bridges (stdp2690, stdp4028) do not probe at the same time, so > the driver does not call ge_b850v3_resgiter() when probing, causing the > driver to try to remove the object that has not been initialized. > > Fix this by checking whether both the bridges are probed. > > Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx> > --- > drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > index cce98bf2a4e7..c68a4cdf4625 100644 > --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > @@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void) > * This check is to avoid both the drivers > * removing the bridge in their remove() function > */ > - if (!ge_b850v3_lvds_ptr) > + if (!ge_b850v3_lvds_ptr || > + !ge_b850v3_lvds_ptr->stdp2690_i2c || > + !ge_b850v3_lvds_ptr->stdp4028_i2c) This chunk fails checkpatch --strict. Alignment should match open parenthesis #39: FILE: drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c:300: > goto out; > > drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge); > -- > 2.25.1 >
