diff options
Diffstat (limited to 'drivers/media/video/gspca')
| -rw-r--r-- | drivers/media/video/gspca/sq905.c | 56 |
1 files changed, 26 insertions, 30 deletions
diff --git a/drivers/media/video/gspca/sq905.c b/drivers/media/video/gspca/sq905.c index 715a68f0156..547d1fd5191 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; @@ -214,7 +218,6 @@ static void sq905_dostream(struct work_struct *work) 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 +225,6 @@ 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 +234,22 @@ 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; @@ -271,7 +267,7 @@ static void sq905_dostream(struct work_struct *work) packet_type = INTER_PACKET; } frame = gspca_get_i_frame(gspca_dev); - if (frame && !discarding) { + if (frame) { frame = gspca_frame_add(gspca_dev, packet_type, frame, data, data_len); /* If entire frame fits in one packet we still @@ -281,23 +277,23 @@ static void sq905_dostream(struct work_struct *work) frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame, data, 0); - } else { - discarding = 1; } } - /* 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; + 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; + } } 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 +342,7 @@ 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. |