[PATCH 5.10 275/352] media: uvcvideo: Fix the bandwdith quirk on USB 3.x

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



5.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michal Pecio <michal.pecio@xxxxxxxxx>

[ Upstream commit 9e3d55fbd160b3ca376599a68b4cddfdc67d4153 ]

The bandwidth fixup quirk doesn't know that SuperSpeed exists and has
the same 8 service intervals per millisecond as High Speed, hence its
calculations are wrong.

Assume that all speeds from HS up use 8 intervals per millisecond.

No further changes are needed, updated code has been confirmed to work
with all speeds from FS to SS.

Signed-off-by: Michal Pecio <michal.pecio@xxxxxxxxx>
Reviewed-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240414190040.2255a0bc@foxbook
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/media/usb/uvc/uvc_video.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 9a4c730943a90..288f097e2e6f2 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -207,13 +207,13 @@ static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
 		/* Compute a bandwidth estimation by multiplying the frame
 		 * size by the number of video frames per second, divide the
 		 * result by the number of USB frames (or micro-frames for
-		 * high-speed devices) per second and add the UVC header size
-		 * (assumed to be 12 bytes long).
+		 * high- and super-speed devices) per second and add the UVC
+		 * header size (assumed to be 12 bytes long).
 		 */
 		bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
 		bandwidth *= 10000000 / interval + 1;
 		bandwidth /= 1000;
-		if (stream->dev->udev->speed == USB_SPEED_HIGH)
+		if (stream->dev->udev->speed >= USB_SPEED_HIGH)
 			bandwidth /= 8;
 		bandwidth += 12;
 
-- 
2.43.0







[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux