em28xx_urb_data_copy() actually consists of two parts:
USB urb processing (checks, data extraction) and frame data packet processing.
Move the latter to a separate function and call it from em28xx_urb_data_copy()
for each data packet.
The em25xx, em2760, em2765 (and likely em277x) chip variants are using a
different frame data format, for which support will be added later with
another function.
This reduces the size of em28xx_urb_data_copy() and makes the code much more
readable. While we're at it, clean up the code a bit (rename some variables to
something more meaningful, improve some comments etc.)
Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx>
---
drivers/media/usb/em28xx/em28xx-video.c | 170 ++++++++++++++++---------------
1 Datei geändert, 90 Zeilen hinzugefügt(+), 80 Zeilen entfernt(-)
diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index 61c7321..fb40d0b 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -379,15 +379,90 @@ finish_field_prepare_next(struct em28xx *dev,
return buf;
}
-/* Processes and copies the URB data content (video and VBI data) */
-static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
+/*
+ * Process data packet according to the em2710/em2750/em28xx frame data format
+ */
+static inline void process_frame_data_em28xx(struct em28xx *dev,
+ unsigned char *data_pkt,
+ unsigned int data_len)
{
- struct em28xx_buffer *buf, *vbi_buf;
+ struct em28xx_buffer *buf = dev->usb_ctl.vid_buf;
+ struct em28xx_buffer *vbi_buf = dev->usb_ctl.vbi_buf;
struct em28xx_dmaqueue *dma_q = &dev->vidq;
struct em28xx_dmaqueue *vbi_dma_q = &dev->vbiq;
- int xfer_bulk, num_packets, i, rc = 1;
- unsigned int actual_length, len = 0;
- unsigned char *p;
+
+ /* capture type 0 = vbi start
+ capture type 1 = vbi in progress
+ capture type 2 = video start
+ capture type 3 = video in progress */
+ if (data_len >= 4) {
+ /* NOTE: Headers are always 4 bytes and
+ * never split across packets */
+ if (data_pkt[0] == 0x88 && data_pkt[1] == 0x88 &&
+ data_pkt[2] == 0x88 && data_pkt[3] == 0x88) {
+ /* Continuation */
+ data_pkt += 4;
+ data_len -= 4;
+ } else if (data_pkt[0] == 0x33 && data_pkt[1] == 0x95) {
+ /* Field start (VBI mode) */
+ dev->capture_type = 0;
+ dev->vbi_read = 0;
+ em28xx_usbdbg("VBI START HEADER !!!\n");
+ dev->top_field = !(data_pkt[2] & 1);
+ data_pkt += 4;
+ data_len -= 4;
+ } else if (data_pkt[0] == 0x22 && data_pkt[1] == 0x5a) {
+ /* Field start (VBI disabled) */
+ dev->capture_type = 2;
+ em28xx_usbdbg("VIDEO START HEADER !!!\n");
+ dev->top_field = !(data_pkt[2] & 1);
+ data_pkt += 4;
+ data_len -= 4;
+ }
+ }
+ /* NOTE: With bulk transfers, intermediate data packets
+ * have no continuation header */
+
+ if (dev->capture_type == 0) {
+ vbi_buf = finish_field_prepare_next(dev, vbi_buf, vbi_dma_q);
+ dev->usb_ctl.vbi_buf = vbi_buf;
+ dev->capture_type = 1;
+ }
+
+ if (dev->capture_type == 1) {
+ int vbi_size = dev->vbi_width * dev->vbi_height;
+ int vbi_data_len = ((dev->vbi_read + data_len) > vbi_size) ?
+ (vbi_size - dev->vbi_read) : data_len;
+
+ /* Copy VBI data */
+ if (vbi_buf != NULL)
+ em28xx_copy_vbi(dev, vbi_buf, data_pkt, vbi_data_len);
+ dev->vbi_read += vbi_data_len;
+
+ if (vbi_data_len < data_len) {
+ /* Continue with copying video data */
+ dev->capture_type = 2;
+ data_pkt += vbi_data_len;
+ data_len -= vbi_data_len;
+ }
+ }
+
+ if (dev->capture_type == 2) {
+ buf = finish_field_prepare_next(dev, buf, dma_q);
+ dev->usb_ctl.vid_buf = buf;
+ dev->capture_type = 3;
+ }
+
+ if (dev->capture_type == 3 && buf != NULL && data_len > 0)
+ em28xx_copy_video(dev, buf, data_pkt, data_len);
+}
+
+/* Processes and copies the URB data content (video and VBI data) */
+static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
+{
+ int xfer_bulk, num_packets, i;
+ unsigned char *usb_data_pkt;
+ unsigned int usb_data_len;
if (!dev)
return 0;
@@ -400,9 +475,6 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
xfer_bulk = usb_pipebulk(urb->pipe);
- buf = dev->usb_ctl.vid_buf;
- vbi_buf = dev->usb_ctl.vbi_buf;
-
if (xfer_bulk) /* bulk */
num_packets = 1;
else /* isoc */
@@ -410,9 +482,9 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
for (i = 0; i < num_packets; i++) {
if (xfer_bulk) { /* bulk */
- actual_length = urb->actual_length;
+ usb_data_len = urb->actual_length;
- p = urb->transfer_buffer;
+ usb_data_pkt = urb->transfer_buffer;
} else { /* isoc */
if (urb->iso_frame_desc[i].status < 0) {
print_err_status(dev, i,
@@ -421,87 +493,25 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
continue;
}
- actual_length = urb->iso_frame_desc[i].actual_length;
- if (actual_length > dev->max_pkt_size) {
+ usb_data_len = urb->iso_frame_desc[i].actual_length;
+ if (usb_data_len > dev->max_pkt_size) {
em28xx_usbdbg("packet bigger than packet size");
continue;
}
- p = urb->transfer_buffer +
- urb->iso_frame_desc[i].offset;
+ usb_data_pkt = urb->transfer_buffer +
+ urb->iso_frame_desc[i].offset;
}
- if (actual_length == 0) {
+ if (usb_data_len == 0) {
/* NOTE: happens very often with isoc transfers */
/* em28xx_usbdbg("packet %d is empty",i); - spammy */
continue;
}
- /* capture type 0 = vbi start
- capture type 1 = vbi in progress
- capture type 2 = video start
- capture type 3 = video in progress */
- len = actual_length;
- if (len >= 4) {
- /* NOTE: headers are always 4 bytes and
- * never split across packets */
- if (p[0] == 0x33 && p[1] == 0x95) {
- dev->capture_type = 0;
- dev->vbi_read = 0;
- em28xx_usbdbg("VBI START HEADER!!!\n");
- dev->top_field = !(p[2] & 1);
- p += 4;
- len -= 4;
- } else if (p[0] == 0x88 && p[1] == 0x88 &&
- p[2] == 0x88 && p[3] == 0x88) {
- /* continuation */
- p += 4;
- len -= 4;
- } else if (p[0] == 0x22 && p[1] == 0x5a) {
- /* start video */
- dev->capture_type = 2;
- dev->top_field = !(p[2] & 1);
- p += 4;
- len -= 4;
- }
- }
- /* NOTE: with bulk transfers, intermediate data packets
- * have no continuation header */
-
- if (dev->capture_type == 0) {
- vbi_buf = finish_field_prepare_next(dev, vbi_buf, vbi_dma_q);
- dev->usb_ctl.vbi_buf = vbi_buf;
- dev->capture_type = 1;
- }
-
- if (dev->capture_type == 1) {
- int vbi_size = dev->vbi_width * dev->vbi_height;
- int vbi_data_len = ((dev->vbi_read + len) > vbi_size) ?
- (vbi_size - dev->vbi_read) : len;
-
- /* Copy VBI data */
- if (vbi_buf != NULL)
- em28xx_copy_vbi(dev, vbi_buf, p, vbi_data_len);
- dev->vbi_read += vbi_data_len;
-
- if (vbi_data_len < len) {
- /* Continue with copying video data */
- dev->capture_type = 2;
- p += vbi_data_len;
- len -= vbi_data_len;
- }
- }
-
- if (dev->capture_type == 2) {
- buf = finish_field_prepare_next(dev, buf, dma_q);
- dev->usb_ctl.vid_buf = buf;
- dev->capture_type = 3;
- }
-
- if (buf != NULL && dev->capture_type == 3 && len > 0)
- em28xx_copy_video(dev, buf, p, len);
+ process_frame_data_em28xx(dev, usb_data_pkt, usb_data_len);
}
- return rc;
+ return 1;
}
--
1.7.10.4
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