diff options
Diffstat (limited to 'linux/drivers/media/video/uvc/uvc_video.c')
| -rw-r--r-- | linux/drivers/media/video/uvc/uvc_video.c | 110 |
1 files changed, 61 insertions, 49 deletions
diff --git a/linux/drivers/media/video/uvc/uvc_video.c b/linux/drivers/media/video/uvc/uvc_video.c index e6f7c3178..04c791213 100644 --- a/linux/drivers/media/video/uvc/uvc_video.c +++ b/linux/drivers/media/video/uvc/uvc_video.c @@ -1,7 +1,7 @@ /* * uvc_video.c -- USB Video Class driver - Video handling * - * Copyright (C) 2005-2008 + * Copyright (C) 2005-2009 * Laurent Pinchart (laurent.pinchart@skynet.be) * * This program is free software; you can redistribute it and/or modify @@ -12,7 +12,6 @@ */ #include <linux/kernel.h> -#include <linux/version.h> #include <linux/list.h> #include <linux/module.h> #include <linux/usb.h> @@ -115,7 +114,7 @@ static int uvc_get_video_ctrl(struct uvc_video_device *video, ctrl->wCompQuality = le16_to_cpup((__le16 *)data); ret = 0; goto out; - } else if (query == GET_DEF && probe == 1) { + } else if (query == GET_DEF && probe == 1 && ret != size) { /* Many cameras don't support the GET_DEF request on their * video probe control. Warn once and return, the caller will * fall back to GET_CUR. @@ -160,7 +159,7 @@ static int uvc_get_video_ctrl(struct uvc_video_device *video, } /* Some broken devices return a null or wrong dwMaxVideoFrameSize. - * Try to get the value from the format and frame descriptor. + * Try to get the value from the format and frame descriptors. */ uvc_fixup_buffer_size(video, ctrl); ret = 0; @@ -191,9 +190,6 @@ static int uvc_set_video_ctrl(struct uvc_video_device *video, *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality); *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize); *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay); - /* Note: Some of the fields below are not required for IN devices (see - * UVC spec, 4.3.1.1), but we still copy them in case support for OUT - * devices is added in the future. */ put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]); put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]); @@ -400,7 +396,7 @@ static int uvc_video_decode_start(struct uvc_video_device *video, * * Empty buffers (bytesused == 0) don't trigger end of frame detection * as it doesn't make sense to return an empty buffer. This also - * avoids detecting and of frame conditions at FID toggling if the + * avoids detecting end of frame conditions at FID toggling if the * previous payload had the EOF bit set. */ if (fid != video->last_fid && buf->buf.bytesused != 0) { @@ -453,6 +449,17 @@ static void uvc_video_decode_end(struct uvc_video_device *video, } } +/* Video payload encoding is handled by uvc_video_encode_header() and + * uvc_video_encode_data(). Only bulk transfers are currently supported. + * + * uvc_video_encode_header is called at the start of a payload. It adds header + * data to the transfer buffer and returns the header size. As the only known + * UVC output device transfers a whole frame in a single payload, the EOF bit + * is always set in the header. + * + * uvc_video_encode_data is called for every URB and copies the data from the + * video buffer to the transfer buffer. + */ static int uvc_video_encode_header(struct uvc_video_device *video, struct uvc_buffer *buf, __u8 *data, int len) { @@ -696,27 +703,47 @@ static void uvc_free_urb_buffers(struct uvc_video_device *video) * already allocated when resuming from suspend, in which case it will * return without touching the buffers. * - * Return 0 on success or -ENOMEM when out of memory. + * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the + * system is too low on memory try successively smaller numbers of packets + * until allocation succeeds. + * + * Return the number of allocated packets on success or 0 when out of memory. */ static int uvc_alloc_urb_buffers(struct uvc_video_device *video, - unsigned int size) + unsigned int size, unsigned int psize, gfp_t gfp_flags) { + unsigned int npackets; unsigned int i; /* Buffers are already allocated, bail out. */ if (video->urb_size) return 0; - for (i = 0; i < UVC_URBS; ++i) { - video->urb_buffer[i] = usb_buffer_alloc(video->dev->udev, - size, GFP_KERNEL, &video->urb_dma[i]); - if (video->urb_buffer[i] == NULL) { - uvc_free_urb_buffers(video); - return -ENOMEM; + /* Compute the number of packets. Bulk endpoints might transfer UVC + * payloads accross multiple URBs. + */ + npackets = DIV_ROUND_UP(size, psize); + if (npackets > UVC_MAX_PACKETS) + npackets = UVC_MAX_PACKETS; + + /* Retry allocations until one succeed. */ + for (; npackets > 1; npackets /= 2) { + for (i = 0; i < UVC_URBS; ++i) { + video->urb_buffer[i] = usb_buffer_alloc( + video->dev->udev, psize * npackets, + gfp_flags | __GFP_NOWARN, &video->urb_dma[i]); + if (!video->urb_buffer[i]) { + uvc_free_urb_buffers(video); + break; + } + } + + if (i == UVC_URBS) { + video->urb_size = psize * npackets; + return npackets; } } - video->urb_size = size; return 0; } @@ -750,29 +777,19 @@ static int uvc_init_video_isoc(struct uvc_video_device *video, { struct urb *urb; unsigned int npackets, i, j; - __u16 psize; - __u32 size; + u16 psize; + u32 size; - /* Compute the number of isochronous packets to allocate by dividing - * the maximum video frame size by the packet size. Limit the result - * to UVC_MAX_ISO_PACKETS. - */ psize = le16_to_cpu(ep->desc.wMaxPacketSize); psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3)); - size = video->streaming->ctrl.dwMaxVideoFrameSize; - if (size > UVC_MAX_FRAME_SIZE) - return -EINVAL; - npackets = DIV_ROUND_UP(size, psize); - if (npackets > UVC_MAX_ISO_PACKETS) - npackets = UVC_MAX_ISO_PACKETS; + npackets = uvc_alloc_urb_buffers(video, size, psize, gfp_flags); + if (npackets == 0) + return -ENOMEM; size = npackets * psize; - if (uvc_alloc_urb_buffers(video, size) < 0) - return -ENOMEM; - for (i = 0; i < UVC_URBS; ++i) { urb = usb_alloc_urb(npackets, gfp_flags); if (urb == NULL) { @@ -811,25 +828,20 @@ static int uvc_init_video_bulk(struct uvc_video_device *video, struct usb_host_endpoint *ep, gfp_t gfp_flags) { struct urb *urb; - unsigned int pipe, i; - __u16 psize; - __u32 size; - - /* Compute the bulk URB size. Some devices set the maximum payload - * size to a value too high for memory-constrained devices. We must - * then transfer the payload accross multiple URBs. To be consistant - * with isochronous mode, allocate maximum UVC_MAX_ISO_PACKETS per bulk - * URB. - */ + unsigned int npackets, pipe, i; + u16 psize; + u32 size; + psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff; size = video->streaming->ctrl.dwMaxPayloadTransferSize; video->bulk.max_payload_size = size; - if (size > psize * UVC_MAX_ISO_PACKETS) - size = psize * UVC_MAX_ISO_PACKETS; - if (uvc_alloc_urb_buffers(video, size) < 0) + npackets = uvc_alloc_urb_buffers(video, size, psize, gfp_flags); + if (npackets == 0) return -ENOMEM; + size = npackets * psize; + if (usb_endpoint_dir_in(&ep->desc)) pipe = usb_rcvbulkpipe(video->dev->udev, ep->desc.bEndpointAddress); @@ -957,7 +969,7 @@ int uvc_video_suspend(struct uvc_video_device *video) } /* - * Reconfigure the video interface and restart streaming if it was enable + * Reconfigure the video interface and restart streaming if it was enabled * before suspend. * * If an error occurs, disable the video queue. This will wake all pending @@ -989,8 +1001,8 @@ int uvc_video_resume(struct uvc_video_device *video) */ /* - * Initialize the UVC video device by retrieving the default format and - * committing it. + * Initialize the UVC video device by switching to alternate setting 0 and + * retrieve the default format. * * Some cameras (namely the Fuji Finepix) set the format and frame * indexes to zero. The UVC standard doesn't clearly make this a spec @@ -1018,7 +1030,7 @@ int uvc_video_init(struct uvc_video_device *video) */ usb_set_interface(video->dev->udev, video->streaming->intfnum, 0); - /* Some webcams don't suport GET_DEF request on the probe control. We + /* Some webcams don't suport GET_DEF requests on the probe control. We * fall back to GET_CUR if GET_DEF fails. */ if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 && |