[PATCH v2] usb: gadget: uvc: add bInterval checking for HS mode
From: Pawel Laszczak <pawell@cadence.com>
Date: 2021-03-08 12:54:48
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Subsystem:
the rest, usb subsystem, usb webcam gadget · Maintainers:
Linus Torvalds, Greg Kroah-Hartman
From: Pawel Laszczak <pawell@cadence.com> 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. Signed-off-by: Pawel Laszczak <pawell@cadence.com> --- Changlog: v2: - removed duplicated assignment drivers/usb/gadget/function/f_uvc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 44b4352a2676..ed77a126a74f 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;
--
2.25.1