diff options
Diffstat (limited to 'drivers/media/video/gspca/sq905.c')
| -rw-r--r-- | drivers/media/video/gspca/sq905.c | 75 |
1 files changed, 33 insertions, 42 deletions
diff --git a/drivers/media/video/gspca/sq905.c b/drivers/media/video/gspca/sq905.c index 715a68f0156e..1fcaca6a87f7 100644 --- a/drivers/media/video/gspca/sq905.c +++ b/drivers/media/video/gspca/sq905.c @@ -168,18 +168,22 @@ static int sq905_ack_frame(struct gspca_dev *gspca_dev) * request and read a block of data - see warning on sq905_command. */ static int -sq905_read_data(struct gspca_dev *gspca_dev, u8 *data, int size) +sq905_read_data(struct gspca_dev *gspca_dev, u8 *data, int size, int need_lock) { int ret; int act_len; gspca_dev->usb_buf[0] = '\0'; + if (need_lock) + mutex_lock(&gspca_dev->usb_lock); ret = usb_control_msg(gspca_dev->dev, usb_sndctrlpipe(gspca_dev->dev, 0), USB_REQ_SYNCH_FRAME, /* request */ USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, SQ905_BULK_READ, size, gspca_dev->usb_buf, 1, SQ905_CMD_TIMEOUT); + if (need_lock) + mutex_unlock(&gspca_dev->usb_lock); if (ret < 0) { PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)", __func__, ret); return ret; @@ -210,11 +214,9 @@ static void sq905_dostream(struct work_struct *work) { struct sd *dev = container_of(work, struct sd, work_struct); struct gspca_dev *gspca_dev = &dev->gspca_dev; - struct gspca_frame *frame; int bytes_left; /* bytes remaining in current frame. */ int data_len; /* size to use for the next read. */ int header_read; /* true if we have already read the frame header. */ - int discarding; /* true if we failed to get space for frame. */ int packet_type; int frame_sz; int ret; @@ -222,7 +224,6 @@ static void sq905_dostream(struct work_struct *work) u8 *buffer; buffer = kmalloc(SQ905_MAX_TRANSFER, GFP_KERNEL | GFP_DMA); - mutex_lock(&gspca_dev->usb_lock); if (!buffer) { PDEBUG(D_ERR, "Couldn't allocate USB buffer"); goto quit_stream; @@ -232,28 +233,22 @@ static void sq905_dostream(struct work_struct *work) + FRAME_HEADER_LEN; while (gspca_dev->present && gspca_dev->streaming) { - /* Need a short delay to ensure streaming flag was set by - * gspca and to make sure gspca can grab the mutex. */ - mutex_unlock(&gspca_dev->usb_lock); - msleep(1); - /* request some data and then read it until we have * a complete frame. */ bytes_left = frame_sz; header_read = 0; - discarding = 0; - while (bytes_left > 0) { + /* Note we do not check for gspca_dev->streaming here, as + we must finish reading an entire frame, otherwise the + next time we stream we start reading in the middle of a + frame. */ + while (bytes_left > 0 && gspca_dev->present) { data_len = bytes_left > SQ905_MAX_TRANSFER ? SQ905_MAX_TRANSFER : bytes_left; - mutex_lock(&gspca_dev->usb_lock); - if (!gspca_dev->present) - goto quit_stream; - ret = sq905_read_data(gspca_dev, buffer, data_len); + ret = sq905_read_data(gspca_dev, buffer, data_len, 1); if (ret < 0) goto quit_stream; - mutex_unlock(&gspca_dev->usb_lock); - PDEBUG(D_STREAM, + PDEBUG(D_PACK, "Got %d bytes out of %d for frame", data_len, bytes_left); bytes_left -= data_len; @@ -270,34 +265,30 @@ static void sq905_dostream(struct work_struct *work) } else { packet_type = INTER_PACKET; } - frame = gspca_get_i_frame(gspca_dev); - if (frame && !discarding) { - frame = gspca_frame_add(gspca_dev, packet_type, - frame, data, data_len); - /* If entire frame fits in one packet we still - need to add a LAST_PACKET */ - if (packet_type == FIRST_PACKET && - bytes_left == 0) - frame = gspca_frame_add(gspca_dev, - LAST_PACKET, - frame, data, 0); - } else { - discarding = 1; - } + gspca_frame_add(gspca_dev, packet_type, + data, data_len); + /* If entire frame fits in one packet we still + need to add a LAST_PACKET */ + if (packet_type == FIRST_PACKET && + bytes_left == 0) + gspca_frame_add(gspca_dev, LAST_PACKET, + NULL, 0); + } + if (gspca_dev->present) { + /* acknowledge the frame */ + mutex_lock(&gspca_dev->usb_lock); + ret = sq905_ack_frame(gspca_dev); + mutex_unlock(&gspca_dev->usb_lock); + if (ret < 0) + goto quit_stream; } - /* acknowledge the frame */ - mutex_lock(&gspca_dev->usb_lock); - if (!gspca_dev->present) - goto quit_stream; - ret = sq905_ack_frame(gspca_dev); - if (ret < 0) - goto quit_stream; } quit_stream: - /* the usb_lock is already acquired */ - if (gspca_dev->present) + if (gspca_dev->present) { + mutex_lock(&gspca_dev->usb_lock); sq905_command(gspca_dev, SQ905_CLEAR); - mutex_unlock(&gspca_dev->usb_lock); + mutex_unlock(&gspca_dev->usb_lock); + } kfree(buffer); } @@ -346,7 +337,7 @@ static int sd_init(struct gspca_dev *gspca_dev) ret = sq905_command(gspca_dev, SQ905_ID); if (ret < 0) return ret; - ret = sq905_read_data(gspca_dev, gspca_dev->usb_buf, 4); + ret = sq905_read_data(gspca_dev, gspca_dev->usb_buf, 4, 0); if (ret < 0) return ret; /* usb_buf is allocated with kmalloc so is aligned. |