Re: [PATCH] stm: ltdc: fix two incorrect NULL checks on list iterator

[Philippe CORNU]

On 3/28/22 14:37, Raphael Gallais-Pou wrote:

Hello Xiaomeng

On 3/27/22 07:53, Xiaomeng Tong wrote:

The two bugs are here:
        if (encoder) {
        if (bridge && bridge->timings)

The list iterator value 'encoder/bridge' will *always* be set and
non-NULL by drm_for_each_encoder()/list_for_each_entry(), so it is
incorrect to assume that the iterator value will be NULL if the
list is empty or no element is found.

To fix the bug, use a new variable '*_iter' as the list iterator,
while use the old variable 'encoder/bridge' as a dedicated pointer
to point to the found element.

Cc: sta...@vger.kernel.org
Fixes: 99e360442f223 ("drm/stm: Fix bus_flags handling")
Signed-off-by: Xiaomeng Tong <xiam0nd.t...@gmail.com>
---
  drivers/gpu/drm/stm/ltdc.c | 16 ++++++++++------
  1 file changed, 10 insertions(+), 6 deletions(-)

Thanks for your fix

Acked-by: Raphael Gallais-Pou <raphael.gallais-...@foss.st.com>


Raphaël Gallais-Pou

Applied on drm-misc-next.
Many thanks for your patch,
Philippe :-)