From 84fbdf87ab8eaa4eaefb317a7eb437cd4d3d0ebf Mon Sep 17 00:00:00 2001 From: Jean-Francois Moine Date: Thu, 19 Mar 2009 06:12:59 -0300 Subject: [PATCH] V4L/DVB (11105): gspca - ov534: Adjust the packet scan function - change max payload size to 2040 bytes (was 2048) - optimize Signed-off-by: Jean-Francois Moine Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/ov534.c | 115 +++++++++++++++--------------- 1 file changed, 57 insertions(+), 58 deletions(-) diff --git a/drivers/media/video/gspca/ov534.c b/drivers/media/video/gspca/ov534.c index ea2245626d5..647c448f492 100644 --- a/drivers/media/video/gspca/ov534.c +++ b/drivers/media/video/gspca/ov534.c @@ -46,9 +46,9 @@ MODULE_LICENSE("GPL"); /* specific webcam descriptor */ struct sd { struct gspca_dev gspca_dev; /* !! must be the first item */ - __u32 last_fid; __u32 last_pts; - int frame_rate; + u16 last_fid; + u8 frame_rate; }; /* V4L2 controls supported by the driver */ @@ -428,76 +428,75 @@ static void sd_pkt_scan(struct gspca_dev *gspca_dev, struct gspca_frame *frame, { struct sd *sd = (struct sd *) gspca_dev; __u32 this_pts; - int this_fid; + u16 this_fid; int remaining_len = len; - __u8 *next_data = data; -scan_next: - if (remaining_len <= 0) - return; - - data = next_data; - len = min(remaining_len, 2048); - remaining_len -= len; - next_data += len; - - /* Payloads are prefixed with a UVC-style header. We - consider a frame to start when the FID toggles, or the PTS - changes. A frame ends when EOF is set, and we've received - the correct number of bytes. */ - - /* Verify UVC header. Header length is always 12 */ - if (data[0] != 12 || len < 12) { - PDEBUG(D_PACK, "bad header"); - goto discard; - } + do { + len = min(remaining_len, 2040); /*fixme: was 2048*/ - /* Check errors */ - if (data[1] & UVC_STREAM_ERR) { - PDEBUG(D_PACK, "payload error"); - goto discard; - } + /* Payloads are prefixed with a UVC-style header. We + consider a frame to start when the FID toggles, or the PTS + changes. A frame ends when EOF is set, and we've received + the correct number of bytes. */ - /* Extract PTS and FID */ - if (!(data[1] & UVC_STREAM_PTS)) { - PDEBUG(D_PACK, "PTS not present"); - goto discard; - } - this_pts = (data[5] << 24) | (data[4] << 16) | (data[3] << 8) | data[2]; - this_fid = (data[1] & UVC_STREAM_FID) ? 1 : 0; - - /* If PTS or FID has changed, start a new frame. */ - if (this_pts != sd->last_pts || this_fid != sd->last_fid) { - gspca_frame_add(gspca_dev, FIRST_PACKET, frame, NULL, 0); - sd->last_pts = this_pts; - sd->last_fid = this_fid; - } - - /* Add the data from this payload */ - gspca_frame_add(gspca_dev, INTER_PACKET, frame, - data + 12, len - 12); + /* Verify UVC header. Header length is always 12 */ + if (data[0] != 12 || len < 12) { + PDEBUG(D_PACK, "bad header"); + goto discard; + } - /* If this packet is marked as EOF, end the frame */ - if (data[1] & UVC_STREAM_EOF) { - sd->last_pts = 0; + /* Check errors */ + if (data[1] & UVC_STREAM_ERR) { + PDEBUG(D_PACK, "payload error"); + goto discard; + } - if ((frame->data_end - frame->data) != - (gspca_dev->width * gspca_dev->height * 2)) { - PDEBUG(D_PACK, "short frame"); + /* Extract PTS and FID */ + if (!(data[1] & UVC_STREAM_PTS)) { + PDEBUG(D_PACK, "PTS not present"); goto discard; } + this_pts = (data[5] << 24) | (data[4] << 16) + | (data[3] << 8) | data[2]; + this_fid = (data[1] & UVC_STREAM_FID) ? 1 : 0; - frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame, + /* If PTS or FID has changed, start a new frame. */ + if (this_pts != sd->last_pts || this_fid != sd->last_fid) { + gspca_frame_add(gspca_dev, FIRST_PACKET, frame, NULL, 0); + sd->last_pts = this_pts; + sd->last_fid = this_fid; + } + + /* Add the data from this payload */ + gspca_frame_add(gspca_dev, INTER_PACKET, frame, + data + 12, len - 12); + + /* If this packet is marked as EOF, end the frame */ + if (data[1] & UVC_STREAM_EOF) { + sd->last_pts = 0; + + if (frame->data_end - frame->data != + gspca_dev->width * gspca_dev->height * 2) { + PDEBUG(D_PACK, "short frame"); + goto discard; + } + + frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame, + NULL, 0); } - /* Done this payload */ - goto scan_next; + /* Done this payload */ + goto scan_next; discard: - /* Discard data until a new frame starts. */ - gspca_frame_add(gspca_dev, DISCARD_PACKET, frame, NULL, 0); - goto scan_next; + /* Discard data until a new frame starts. */ + gspca_frame_add(gspca_dev, DISCARD_PACKET, frame, NULL, 0); + +scan_next: + remaining_len -= len; + data += len; + } while (remaining_len > 0); } /* get stream parameters (framerate) */ -- 2.41.1