From: Michal Pecio <michal.pecio@gmail.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-media@vger.kernel.org
Subject: [PATCH] media: uvcvideo: extend the bandwdith quirk to USB 3.x
Date: Sun, 14 Jan 2024 21:35:18 +0100 [thread overview]
Message-ID: <20240114213518.03e22698@foxbook> (raw)
The bandwidth fixup quirk which is needed to run certain buggy cameras
doesn't know that SuperSpeed exists and has the same 8 service intervals
per millisecond as High Speed; hence its calculations are badly wrong.
Assume that all speeds from HS up use 8 intervals per millisecond.
No further changes are required. Updated code has been confirmed to work
properly with a SuperSpeed camera, as well as some High Speed ones.
Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
---
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 28dde08ec6c5..4b86bef06a52 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
next reply other threads:[~2024-01-14 20:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-14 20:35 Michal Pecio [this message]
2024-01-14 22:58 ` [PATCH] media: uvcvideo: extend the bandwdith quirk to USB 3.x Ricardo Ribalda
2024-01-14 23:57 ` Michał Pecio
2024-01-18 11:30 ` Michał Pecio
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