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Message-Id: <20210510101951.650843594@linuxfoundation.org>
Date: Mon, 10 May 2021 12:18:58 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Peter Chen <peter.chen@...nel.org>,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Pawel Laszczak <pawell@...ence.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 044/184] usb: gadget: uvc: add bInterval checking for HS mode
From: Pawel Laszczak <pawell@...ence.com>
[ 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@...nel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
Signed-off-by: Pawel Laszczak <pawell@...ence.com>
Link: https://lore.kernel.org/r/20210308125338.4824-1-pawell@gli-login.cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
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 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;
--
2.30.2
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