On 27/08/2021 18:39, Paul Cercueil wrote:

If run before the next bridge is initialized, of_drm_find_bridge() will give us a NULL pointer.

If that's the case, return -EPROBE_DEFER; we may have more luck next time.

Fixes: 988156dc2fc9 ("drm: bridge: add it66121 driver")

Signed-off-by: Paul Cercueil paul@crapouillou.net

drivers/gpu/drm/bridge/ite-it66121.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c index b130d01147c6..9dc41a7b9136 100644 --- a/drivers/gpu/drm/bridge/ite-it66121.c +++ b/drivers/gpu/drm/bridge/ite-it66121.c @@ -924,6 +924,9 @@ static int it66121_probe(struct i2c_client *client, ctx->next_bridge = of_drm_find_bridge(ep); of_node_put(ep);

• if (!ctx->next_bridge)

• return -EPROBE_DEFER;
  

• i2c_set_clientdata(client, ctx); mutex_init(&ctx->lock);

Reviewed-by: Neil Armstrong narmstrong@baylibre.com

Thanks, Neil

On Mon, 30 Aug 2021 at 11:40, Neil Armstrong narmstrong@baylibre.com wrote:

On 27/08/2021 18:39, Paul Cercueil wrote:

...

These two arrays are populated with data read from the I2C device through regmap_read(), and the data is then compared with hardcoded vendor/product ID values of supported chips.

However, the return value of regmap_read() was never checked. This is fine, as long as the two arrays are zero-initialized, so that we don't compare the vendor/product IDs against whatever garbage is left on the stack.

Address this issue by zero-initializing these two arrays.

Fixes: 988156dc2fc9 ("drm: bridge: add it66121 driver")

...

Signed-off-by: Paul Cercueil paul@crapouillou.net

drivers/gpu/drm/bridge/ite-it66121.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c index 2f2a09adb4bc..b130d01147c6 100644 --- a/drivers/gpu/drm/bridge/ite-it66121.c +++ b/drivers/gpu/drm/bridge/ite-it66121.c @@ -889,7 +889,7 @@ static irqreturn_t it66121_irq_threaded_handler(int irq, void *dev_id) static int it66121_probe(struct i2c_client *client, const struct i2c_device_id *id) {

• u32 vendor_ids[2], device_ids[2], revision_id;
  

• u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
  struct device_node *ep;
  int ret;
  struct it66121_ctx *ctx;
  
  

Reviewed-by: Neil Armstrong narmstrong@baylibre.com

Applied series to drm-misc-next.