The intervals pointer is incremented for each interval when parsing the
format descriptor. This doesn't cause any issue as such, but gets in the
way of constifying some pointers. Modify the parsing code to index the
intervals pointer as an array and increment it in one go at end of
parsing.
Careful readers will notice that the maxIntervalIndex variable is set to
1 instead of n - 2 when bFrameIntervalType has a zero value. This is
functionally equivalent, as n is equal to 3 in that case.
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_driver.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 446bd8ff128c..11e4fa007f3f 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -370,6 +370,8 @@ static int uvc_parse_format(struct uvc_device *dev,
*/
while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
buffer[2] == ftype) {
+ unsigned int maxIntervalIndex;
+
frame = &format->frames[format->nframes];
if (ftype != UVC_VS_FRAME_FRAME_BASED)
n = buflen > 25 ? buffer[25] : 0;
@@ -418,7 +420,7 @@ static int uvc_parse_format(struct uvc_device *dev,
for (i = 0; i < n; ++i) {
interval = get_unaligned_le32(&buffer[26+4*i]);
- *(*intervals)++ = interval ? interval : 1;
+ (*intervals)[i] = interval ? interval : 1;
}
/*
@@ -440,11 +442,11 @@ static int uvc_parse_format(struct uvc_device *dev,
* frame->wWidth * frame->wHeight / 8;
/* Clamp the default frame interval to the boundaries. */
- n -= frame->bFrameIntervalType ? 1 : 2;
+ maxIntervalIndex = frame->bFrameIntervalType ? n - 1 : 1;
frame->dwDefaultFrameInterval =
clamp(frame->dwDefaultFrameInterval,
frame->dwFrameInterval[0],
- frame->dwFrameInterval[n]);
+ frame->dwFrameInterval[maxIntervalIndex]);
/*
* Some devices report frame intervals that are not functional.
@@ -463,6 +465,8 @@ static int uvc_parse_format(struct uvc_device *dev,
(100000000 / frame->dwDefaultFrameInterval) % 10);
format->nframes++;
+ *intervals += n;
+
buflen -= buffer[0];
buffer += buffer[0];
}
--
Regards,
Laurent Pinchart
