V4L/DVB (11835): uvcvideo: Parse frame descriptors with non-continuous indexes.

The UVC specification requires frame descriptors indexes to range from 1 to
the number of frame descriptors. At least some Hercules Dualpix Infinite
webcams erroneously use non-continuous index ranges. Make the driver support
them.

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

2 files changed, 13 insertions, 28 deletions

diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
index 507dc85646b2..34cd36037f11 100644
--- a/drivers/media/video/uvc/uvc_driver.c
+++ b/drivers/media/video/uvc/uvc_driver.c
@@ -289,10 +289,8 @@ static int uvc_parse_format(struct uvc_device *dev,
         struct uvc_format_desc *fmtdesc;
         struct uvc_frame *frame;
         const unsigned char *start = buffer;
-        unsigned char *_buffer;
         unsigned int interval;
         unsigned int i, n;
-        int _buflen;
         __u8 ftype;
 
         format->type = buffer[2];
@@ -413,20 +411,11 @@ static int uvc_parse_format(struct uvc_device *dev,
         buflen -= buffer[0];
         buffer += buffer[0];
 
-        /* Count the number of frame descriptors to test the bFrameIndex
-         * field when parsing the descriptors. We can't rely on the
-         * bNumFrameDescriptors field as some cameras don't initialize it
-         * properly.
-         */
-        for (_buflen = buflen, _buffer = buffer;
-             _buflen > 2 && _buffer[2] == ftype;
-             _buflen -= _buffer[0], _buffer += _buffer[0])
-                format->nframes++;
-
         /* Parse the frame descriptors. Only uncompressed, MJPEG and frame
          * based formats have frame descriptors.
          */
         while (buflen > 2 && buffer[2] == ftype) {
+                frame = &format->frame[format->nframes];
                 if (ftype != VS_FRAME_FRAME_BASED)
                         n = buflen > 25 ? buffer[25] : 0;
                 else
@@ -441,16 +430,6 @@ static int uvc_parse_format(struct uvc_device *dev,
                         return -EINVAL;
                 }
 
-                if (buffer[3] - 1 >= format->nframes) {
-                        uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
-                               "interface %d frame index %u out of range\n",
-                               dev->udev->devnum, alts->desc.bInterfaceNumber,
-                               buffer[3]);
-                        return -EINVAL;
-                }
-
-                frame = &format->frame[buffer[3] - 1];
-
                 frame->bFrameIndex = buffer[3];
                 frame->bmCapabilities = buffer[4];
                 frame->wWidth = get_unaligned_le16(&buffer[5]);
@@ -507,6 +486,7 @@ static int uvc_parse_format(struct uvc_device *dev,
                         10000000/frame->dwDefaultFrameInterval,
                         (100000000/frame->dwDefaultFrameInterval)%10);
 
+                format->nframes++;
                 buflen -= buffer[0];
                 buffer += buffer[0];
         }
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 6ce974d7362f..01b633c73480 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -65,7 +65,8 @@ static void uvc_fixup_video_ctrl(struct uvc_video_device *video,
         struct uvc_streaming_control *ctrl)
 {
         struct uvc_format *format;
-        struct uvc_frame *frame;
+        struct uvc_frame *frame = NULL;
+        unsigned int i;
 
         if (ctrl->bFormatIndex <= 0 ||
             ctrl->bFormatIndex > video->streaming->nformats)
@@ -73,11 +74,15 @@ static void uvc_fixup_video_ctrl(struct uvc_video_device *video,
 
         format = &video->streaming->format[ctrl->bFormatIndex - 1];
 
-        if (ctrl->bFrameIndex <= 0 ||
-            ctrl->bFrameIndex > format->nframes)
-                return;
+        for (i = 0; i < format->nframes; ++i) {
+                if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
+                        frame = &format->frame[i];
+                        break;
+                }
+        }
 
-        frame = &format->frame[ctrl->bFrameIndex - 1];
+        if (frame == NULL)
+                return;
 
         if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
              (ctrl->dwMaxVideoFrameSize == 0 &&
@@ -1089,7 +1094,7 @@ int uvc_video_init(struct uvc_video_device *video)
         /* Zero bFrameIndex might be correct. Stream-based formats (including
          * MPEG-2 TS and DV) do not support frames but have a dummy frame
          * descriptor with bFrameIndex set to zero. If the default frame
-         * descriptor is not found, use the first avalable frame.
+         * descriptor is not found, use the first available frame.
          */
         for (i = format->nframes; i > 0; --i) {
                 frame = &format->frame[i-1];