[PATCH AUTOSEL 6.10 24/34] media: uvcvideo: Fix the bandwdith quirk on USB 3.x

Sasha Levin
2024-07-28T15:44:43Z

From: Michal Pecio <michal.pecio@gmail.com>

[ 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@gmail.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20240414190040.2255a0bc@foxbook
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 11ef12d4fb698..20b03dd725201 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -214,13 +214,13 @@ 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