V4L/DVB (10652): uvcvideo: Add quirk to override wrong bandwidth value for Vimicro...

At least 3 Vimicro cameras (0x332d, 0x3410 and 0x3420) fail to return correct
bandwidth information. The first model rounds the value provided by the host
to the nearest supported packet size, while the other two always request the
maximum bandwidth.

Introduce a device quirk to override the value returned by the device with an
estimated bandwidth computed by the driver from the frame size and frame rate,
and enable it for all Vimicro cameras.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
index ebcd5bf..22e2783 100644 (file)
--- a/drivers/media/video/uvc/uvc_driver.c
+++ b/drivers/media/video/uvc/uvc_driver.c
@@ -1861,6 +1861,15 @@ static struct usb_device_id uvc_ids[] = {
          .bInterfaceSubClass   = 1,
          .bInterfaceProtocol   = 0,
          .driver_info          = UVC_QUIRK_STREAM_NO_FID },
+       /* ViMicro */
+       { .match_flags          = USB_DEVICE_ID_MATCH_VENDOR
+                               | USB_DEVICE_ID_MATCH_INT_INFO,
+         .idVendor             = 0x0ac8,
+         .idProduct            = 0x0000,
+         .bInterfaceClass      = USB_CLASS_VIDEO,
+         .bInterfaceSubClass   = 1,
+         .bInterfaceProtocol   = 0,
+         .driver_info          = UVC_QUIRK_FIX_BANDWIDTH },
        /* MT6227 */
        { .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
                                | USB_DEVICE_ID_MATCH_INT_INFO,

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 0789ba3..a95e173 100644 (file)
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -61,7 +61,7 @@ int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
        return 0;
 }
 
-static void uvc_fixup_buffer_size(struct uvc_video_device *video,
+static void uvc_fixup_video_ctrl(struct uvc_video_device *video,
        struct uvc_streaming_control *ctrl)
 {
        struct uvc_format *format;
@@ -84,6 +84,31 @@ static void uvc_fixup_buffer_size(struct uvc_video_device *video,
              video->dev->uvc_version < 0x0110))
                ctrl->dwMaxVideoFrameSize =
                        frame->dwMaxVideoFrameBufferSize;
+
+       if (video->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
+           video->streaming->intf->num_altsetting > 1) {
+               u32 interval;
+               u32 bandwidth;
+
+               interval = (ctrl->dwFrameInterval > 100000)
+                        ? ctrl->dwFrameInterval
+                        : frame->dwFrameInterval[0];
+
+               /* 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).
+                */
+               bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
+               bandwidth *= 10000000 / interval + 1;
+               bandwidth /= 1000;
+               if (video->dev->udev->speed == USB_SPEED_HIGH)
+                       bandwidth /= 8;
+               bandwidth += 12;
+
+               ctrl->dwMaxPayloadTransferSize = bandwidth;
+       }
 }
 
 static int uvc_get_video_ctrl(struct uvc_video_device *video,
@@ -158,10 +183,11 @@ static int uvc_get_video_ctrl(struct uvc_video_device *video,
                ctrl->bMaxVersion = 0;
        }
 
-       /* Some broken devices return a null or wrong dwMaxVideoFrameSize.
-        * Try to get the value from the format and frame descriptors.
+       /* Some broken devices return null or wrong dwMaxVideoFrameSize and
+        * dwMaxPayloadTransferSize fields. Try to get the value from the
+        * format and frame descriptors.
         */
-       uvc_fixup_buffer_size(video, ctrl);
+       uvc_fixup_video_ctrl(video, ctrl);
        ret = 0;
 
 out:

diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
index 6f55c4d..e5014e6 100644 (file)
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -314,6 +314,7 @@ struct uvc_xu_control {
 #define UVC_QUIRK_STREAM_NO_FID                0x00000010
 #define UVC_QUIRK_IGNORE_SELECTOR_UNIT 0x00000020
 #define UVC_QUIRK_PRUNE_CONTROLS       0x00000040
+#define UVC_QUIRK_FIX_BANDWIDTH                0x00000080
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED                0x00000001