The ftype value does not change in the while loop so we can check it
before entering the while loop. Refactoring the frame parsing code into
a dedicated uvc_parse_frame function makes this more readable.
Signed-off-by: Benoit Sevens <bsevens@xxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_driver.c | 228 ++++++++++++++++-------------
1 file changed, 123 insertions(+), 105 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 13db0026dc1a..99f811ace5d6 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -220,6 +220,117 @@ static struct uvc_streaming *uvc_stream_new(struct uvc_device *dev,
* Descriptors parsing
*/
+static int uvc_parse_frame(struct uvc_device *dev, struct uvc_streaming *streaming,
+ struct uvc_format *format, struct uvc_frame *frame, u32 **intervals,
+ u8 ftype, int width_multiplier, const unsigned char *buffer, int buflen)
+{
+ struct usb_interface *intf = streaming->intf;
+ struct usb_host_interface *alts = intf->cur_altsetting;
+ unsigned int i, n;
+ unsigned int interval;
+ unsigned int maxIntervalIndex;
+
+ if (ftype != UVC_VS_FRAME_FRAME_BASED)
+ n = buflen > 25 ? buffer[25] : 0;
+ else
+ n = buflen > 21 ? buffer[21] : 0;
+
+ n = n ? n : 3;
+
+ if (buflen < 26 + 4*n) {
+ uvc_dbg(dev, DESCR,
+ "device %d videostreaming interface %d FRAME error\n",
+ dev->udev->devnum,
+ alts->desc.bInterfaceNumber);
+ return -EINVAL;
+ }
+
+ frame->bFrameIndex = buffer[3];
+ frame->bmCapabilities = buffer[4];
+ frame->wWidth = get_unaligned_le16(&buffer[5])
+ * width_multiplier;
+ frame->wHeight = get_unaligned_le16(&buffer[7]);
+ frame->dwMinBitRate = get_unaligned_le32(&buffer[9]);
+ frame->dwMaxBitRate = get_unaligned_le32(&buffer[13]);
+ if (ftype != UVC_VS_FRAME_FRAME_BASED) {
+ frame->dwMaxVideoFrameBufferSize =
+ get_unaligned_le32(&buffer[17]);
+ frame->dwDefaultFrameInterval =
+ get_unaligned_le32(&buffer[21]);
+ frame->bFrameIntervalType = buffer[25];
+ } else {
+ frame->dwMaxVideoFrameBufferSize = 0;
+ frame->dwDefaultFrameInterval =
+ get_unaligned_le32(&buffer[17]);
+ frame->bFrameIntervalType = buffer[21];
+ }
+
+ /*
+ * Copy the frame intervals.
+ *
+ * Some bogus devices report dwMinFrameInterval equal to
+ * dwMaxFrameInterval and have dwFrameIntervalStep set to
+ * zero. Setting all null intervals to 1 fixes the problem and
+ * some other divisions by zero that could happen.
+ */
+ frame->dwFrameInterval = *intervals;
+
+ for (i = 0; i < n; ++i) {
+ interval = get_unaligned_le32(&buffer[26+4*i]);
+ (*intervals)[i] = interval ? interval : 1;
+ }
+
+ /*
+ * Apply more fixes, quirks and workarounds to handle incorrect
+ * or broken descriptors.
+ */
+
+ /*
+ * Several UVC chipsets screw up dwMaxVideoFrameBufferSize
+ * completely. Observed behaviours range from setting the
+ * value to 1.1x the actual frame size to hardwiring the
+ * 16 low bits to 0. This results in a higher than necessary
+ * memory usage as well as a wrong image size information. For
+ * uncompressed formats this can be fixed by computing the
+ * value from the frame size.
+ */
+ if (!(format->flags & UVC_FMT_FLAG_COMPRESSED))
+ frame->dwMaxVideoFrameBufferSize = format->bpp
+ * frame->wWidth * frame->wHeight / 8;
+
+ /*
+ * Clamp the default frame interval to the boundaries. A zero
+ * bFrameIntervalType value indicates a continuous frame
+ * interval range, with dwFrameInterval[0] storing the minimum
+ * value and dwFrameInterval[1] storing the maximum value.
+ */
+ maxIntervalIndex = frame->bFrameIntervalType ? n - 1 : 1;
+ frame->dwDefaultFrameInterval =
+ clamp(frame->dwDefaultFrameInterval,
+ frame->dwFrameInterval[0],
+ frame->dwFrameInterval[maxIntervalIndex]);
+
+ /*
+ * Some devices report frame intervals that are not functional.
+ * If the corresponding quirk is set, restrict operation to the
+ * first interval only.
+ */
+ if (dev->quirks & UVC_QUIRK_RESTRICT_FRAME_RATE) {
+ frame->bFrameIntervalType = 1;
+ (*intervals)[0] = frame->dwDefaultFrameInterval;
+ }
+
+ uvc_dbg(dev, DESCR, "- %ux%u (%u.%u fps)\n",
+ frame->wWidth, frame->wHeight,
+ 10000000 / frame->dwDefaultFrameInterval,
+ (100000000 / frame->dwDefaultFrameInterval) % 10);
+
+ *intervals += n;
+
+ return buffer[0];
+}
+
+
static int uvc_parse_format(struct uvc_device *dev,
struct uvc_streaming *streaming, struct uvc_format *format,
struct uvc_frame *frames, u32 **intervals, const unsigned char *buffer,
@@ -231,9 +342,9 @@ static int uvc_parse_format(struct uvc_device *dev,
struct uvc_frame *frame;
const unsigned char *start = buffer;
unsigned int width_multiplier = 1;
- unsigned int interval;
unsigned int i, n;
u8 ftype;
+ int ret;
format->type = buffer[2];
format->index = buffer[3];
@@ -371,111 +482,18 @@ static int uvc_parse_format(struct uvc_device *dev,
* Parse the frame descriptors. Only uncompressed, MJPEG and frame
* based formats have frame descriptors.
*/
- while (ftype && buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
- buffer[2] == ftype) {
- unsigned int maxIntervalIndex;
-
- frame = &frames[format->nframes];
- if (ftype != UVC_VS_FRAME_FRAME_BASED)
- n = buflen > 25 ? buffer[25] : 0;
- else
- n = buflen > 21 ? buffer[21] : 0;
-
- n = n ? n : 3;
-
- if (buflen < 26 + 4*n) {
- uvc_dbg(dev, DESCR,
- "device %d videostreaming interface %d FRAME error\n",
- dev->udev->devnum,
- alts->desc.bInterfaceNumber);
- return -EINVAL;
- }
-
- frame->bFrameIndex = buffer[3];
- frame->bmCapabilities = buffer[4];
- frame->wWidth = get_unaligned_le16(&buffer[5])
- * width_multiplier;
- frame->wHeight = get_unaligned_le16(&buffer[7]);
- frame->dwMinBitRate = get_unaligned_le32(&buffer[9]);
- frame->dwMaxBitRate = get_unaligned_le32(&buffer[13]);
- if (ftype != UVC_VS_FRAME_FRAME_BASED) {
- frame->dwMaxVideoFrameBufferSize =
- get_unaligned_le32(&buffer[17]);
- frame->dwDefaultFrameInterval =
- get_unaligned_le32(&buffer[21]);
- frame->bFrameIntervalType = buffer[25];
- } else {
- frame->dwMaxVideoFrameBufferSize = 0;
- frame->dwDefaultFrameInterval =
- get_unaligned_le32(&buffer[17]);
- frame->bFrameIntervalType = buffer[21];
- }
-
- /*
- * Copy the frame intervals.
- *
- * Some bogus devices report dwMinFrameInterval equal to
- * dwMaxFrameInterval and have dwFrameIntervalStep set to
- * zero. Setting all null intervals to 1 fixes the problem and
- * some other divisions by zero that could happen.
- */
- frame->dwFrameInterval = *intervals;
-
- for (i = 0; i < n; ++i) {
- interval = get_unaligned_le32(&buffer[26+4*i]);
- (*intervals)[i] = interval ? interval : 1;
- }
-
- /*
- * Apply more fixes, quirks and workarounds to handle incorrect
- * or broken descriptors.
- */
-
- /*
- * Several UVC chipsets screw up dwMaxVideoFrameBufferSize
- * completely. Observed behaviours range from setting the
- * value to 1.1x the actual frame size to hardwiring the
- * 16 low bits to 0. This results in a higher than necessary
- * memory usage as well as a wrong image size information. For
- * uncompressed formats this can be fixed by computing the
- * value from the frame size.
- */
- if (!(format->flags & UVC_FMT_FLAG_COMPRESSED))
- frame->dwMaxVideoFrameBufferSize = format->bpp
- * frame->wWidth * frame->wHeight / 8;
-
- /*
- * Clamp the default frame interval to the boundaries. A zero
- * bFrameIntervalType value indicates a continuous frame
- * interval range, with dwFrameInterval[0] storing the minimum
- * value and dwFrameInterval[1] storing the maximum value.
- */
- maxIntervalIndex = frame->bFrameIntervalType ? n - 1 : 1;
- frame->dwDefaultFrameInterval =
- clamp(frame->dwDefaultFrameInterval,
- frame->dwFrameInterval[0],
- frame->dwFrameInterval[maxIntervalIndex]);
-
- /*
- * Some devices report frame intervals that are not functional.
- * If the corresponding quirk is set, restrict operation to the
- * first interval only.
- */
- if (dev->quirks & UVC_QUIRK_RESTRICT_FRAME_RATE) {
- frame->bFrameIntervalType = 1;
- (*intervals)[0] = frame->dwDefaultFrameInterval;
+ if (ftype) {
+ while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+ buffer[2] == ftype) {
+ frame = &frames[format->nframes];
+ ret = uvc_parse_frame(dev, streaming, format, frame, intervals, ftype,
+ width_multiplier, buffer, buflen);
+ if (ret < 0)
+ return ret;
+ format->nframes++;
+ buflen -= ret;
+ buffer += ret;
}
-
- uvc_dbg(dev, DESCR, "- %ux%u (%u.%u fps)\n",
- frame->wWidth, frame->wHeight,
- 10000000 / frame->dwDefaultFrameInterval,
- (100000000 / frame->dwDefaultFrameInterval) % 10);
-
- format->nframes++;
- *intervals += n;
-
- buflen -= buffer[0];
- buffer += buffer[0];
}
if (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
--
2.47.0.277.g8800431eea-goog
