This is a note to let you know that I've just added the patch titled
usb: gadget: uvc: add bInterval checking for HS mode
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-gadget-uvc-add-binterval-checking-for-hs-mode.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 49794ca9080606570c60222441cedbef1346028c
Author: Pawel Laszczak <pawell@xxxxxxxxxxx>
Date: Mon Mar 8 13:53:38 2021 +0100
usb: gadget: uvc: add bInterval checking for HS mode
[ Upstream commit 26adde04acdff14a1f28d4a5dce46a8513a3038b ]
Patch adds extra checking for bInterval passed by configfs.
The 5.6.4 chapter of USB Specification (rev. 2.0) say:
"A high-bandwidth endpoint must specify a period of 1x125 µs
(i.e., a bInterval value of 1)."
The issue was observed during testing UVC class on CV.
I treat this change as improvement because we can control
bInterval by configfs.
Reviewed-by: Peter Chen <peter.chen@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210308125338.4824-1-pawell@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index fb0a892687c0..79ecdbb936c1 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -633,7 +633,12 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
uvc_hs_streaming_ep.wMaxPacketSize =
cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
- uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
+
+ /* A high-bandwidth endpoint must specify a bInterval value of 1 */
+ if (max_packet_mult > 1)
+ uvc_hs_streaming_ep.bInterval = 1;
+ else
+ uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
