From: Pawel Laszczak <pawell@cadence.com>
To: <balbi@kernel.org>
Cc: <laurent.pinchart@ideasonboard.com>, <gregkh@linuxfoundation.org>,
<linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<peter.chen@kernel.org>, <kurahul@cadence.com>,
Pawel Laszczak <pawell@cadence.com>
Subject: [PATCH v2] usb: gadget: uvc: add bInterval checking for HS mode
Date: Mon, 8 Mar 2021 13:53:38 +0100 [thread overview]
Message-ID: <20210308125338.4824-1-pawell@gli-login.cadence.com> (raw)
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
next reply other threads:[~2021-03-08 12:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-08 12:53 Pawel Laszczak [this message]
2021-03-14 2:29 ` [PATCH v2] usb: gadget: uvc: add bInterval checking for HS mode Peter Chen
2021-03-14 2:40 ` Laurent Pinchart
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