diff mbox series

[v6,03/11] media: uvcvideo: Allow entities with no pads

Message ID 20201222230446.1027916-4-ribalda@chromium.org
State Superseded
Headers show
Series [v6,01/11] media: uvcvideo: Move guid to entity | expand

Commit Message

Ricardo Ribalda Dec. 22, 2020, 11:04 p.m. UTC 
Avoid an underflow while calculating the number of inputs for entities
with zero pads.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_driver.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 82cdd1bb28dc..c0c5f75ade40 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1033,7 +1033,10 @@  static struct uvc_entity *uvc_alloc_entity(u16 type, u16 id,
 	unsigned int i;
 
 	extra_size = roundup(extra_size, sizeof(*entity->pads));
-	num_inputs = (type & UVC_TERM_OUTPUT) ? num_pads : num_pads - 1;
+	if (num_pads)
+		num_inputs = type & UVC_TERM_OUTPUT ? num_pads : num_pads - 1;
+	else
+		num_inputs = 0;
 	size = sizeof(*entity) + extra_size + sizeof(*entity->pads) * num_pads
 	     + num_inputs;
 	entity = kzalloc(size, GFP_KERNEL);
@@ -1065,7 +1068,7 @@  static struct uvc_entity *uvc_alloc_entity(u16 type, u16 id,
 
 	for (i = 0; i < num_inputs; ++i)
 		entity->pads[i].flags = MEDIA_PAD_FL_SINK;
-	if (!UVC_ENTITY_IS_OTERM(entity))
+	if (!UVC_ENTITY_IS_OTERM(entity) && num_pads)
 		entity->pads[num_pads-1].flags = MEDIA_PAD_FL_SOURCE;
 
 	entity->bNrInPins = num_inputs;