diff options
| author | Ming Lei <tom.leiming@gmail.com> | 2008-09-16 03:32:20 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2008-10-12 09:37:08 -0200 |
| commit | a31a4055473bf0a7b2b06cb2262347200d0711e1 (patch) | |
| tree | 296667c25e67acd933c55c71b85b619b5918ae5e /drivers | |
| parent | d63beb9ef004ff9587b3c466361276254d57d7a7 (diff) | |
V4L/DVB:usbvideo:don't use part of buffer for USB transfer #4
The status[] is part of uvc_device structure. We can't make sure
the address of status is at a cache-line boundary in all archs,so
status[] might share a cache-line with some fields in uvc_structure.
This can lead to some cache coherence issues(http://lwn.net/Articles/2265/).
Use dynamically allocated buffer instead.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/video/uvc/uvc_status.c | 11 | ||||
| -rw-r--r-- | drivers/media/video/uvc/uvcvideo.h | 4 |
2 files changed, 12 insertions, 3 deletions
diff --git a/drivers/media/video/uvc/uvc_status.c b/drivers/media/video/uvc/uvc_status.c index 75e678ac54e..5d60b264d59 100644 --- a/drivers/media/video/uvc/uvc_status.c +++ b/drivers/media/video/uvc/uvc_status.c @@ -177,9 +177,15 @@ int uvc_status_init(struct uvc_device *dev) uvc_input_init(dev); + dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL); + if (dev->status == NULL) + return -ENOMEM; + dev->int_urb = usb_alloc_urb(0, GFP_KERNEL); - if (dev->int_urb == NULL) + if (dev->int_urb == NULL) { + kfree(dev->status); return -ENOMEM; + } pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress); @@ -192,7 +198,7 @@ int uvc_status_init(struct uvc_device *dev) interval = fls(interval) - 1; usb_fill_int_urb(dev->int_urb, dev->udev, pipe, - dev->status, sizeof dev->status, uvc_status_complete, + dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete, dev, interval); return usb_submit_urb(dev->int_urb, GFP_KERNEL); @@ -202,6 +208,7 @@ void uvc_status_cleanup(struct uvc_device *dev) { usb_kill_urb(dev->int_urb); usb_free_urb(dev->int_urb); + kfree(dev->status); uvc_input_cleanup(dev); } diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h index bafe3406e30..9a6bc1aafb1 100644 --- a/drivers/media/video/uvc/uvcvideo.h +++ b/drivers/media/video/uvc/uvcvideo.h @@ -303,6 +303,8 @@ struct uvc_xu_control { #define UVC_MAX_FRAME_SIZE (16*1024*1024) /* Maximum number of video buffers. */ #define UVC_MAX_VIDEO_BUFFERS 32 +/* Maximum status buffer size in bytes of interrupt URB. */ +#define UVC_MAX_STATUS_SIZE 16 #define UVC_CTRL_CONTROL_TIMEOUT 300 #define UVC_CTRL_STREAMING_TIMEOUT 1000 @@ -634,7 +636,7 @@ struct uvc_device { /* Status Interrupt Endpoint */ struct usb_host_endpoint *int_ep; struct urb *int_urb; - __u8 status[16]; + __u8 *status; struct input_dev *input; /* Video Streaming interfaces */ |