gpu: drm: xylon: Return error if i2c client driver is NULL

Return error if i2c_client driver instance is NULL. Incase i2c encoder(adv7511) probe fails not checking it will result in NULL pointer dereference. <snip> Unable to handle kernel NULL pointer dereference at virtual address 00000050 pgd = 40004000 [00000050] *pgd=00000000 Internal error: Oops - BUG: 17 [parallella#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 690 Comm: kworker/u4:2 Not tainted 3.19.0-xilinx-13711-g2b55e97-dirty analogdevicesinc#49 Hardware name: Xilinx Zynq Platform Workqueue: deferwq deferred_probe_work_func task: 771ab100 ti: 72a42000 task.ti: 72a42000 PC is at xylon_drm_encoder_create+0xf4/0x188 LR is at xylon_drm_encoder_create+0xf4/0x188 Signed-off-by: Radhey Shyam Pandey <[email protected]> Signed-off-by: Michal Simek <[email protected]> Tested-by: Christian Kohn <[email protected]>
olajep · May 22, 2015 · 64e0529 · 64e0529
1 parent e19a2c3
commit 64e0529
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/gpu/drm/xylon/xylon_encoder.c b/drivers/gpu/drm/xylon/xylon_encoder.c
@@ -187,7 +187,7 @@ struct drm_encoder *xylon_drm_encoder_create(struct drm_device *dev)
 
 	encoder->client = of_find_i2c_device_by_node(sub_node);
 	of_node_put(sub_node);
-	if (!encoder->client) {
+	if (!encoder->client || !encoder->client->dev.driver) {
 		DRM_INFO("failed find encoder\n");
 		return ERR_PTR(-EPROBE_DEFER);
 	}