[media] pwc: Avoid sending mode info to the camera when it is not needed

Since we always do a set_video_mode on stream start, there is no need
to actually send the mode info to the device on a s_fmt / s_parm ioctl.
Not doing this saves us doing (slow) usb io.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/pwc/pwc-ctrl.c

@@ -169,10 +169,10 @@ int send_control_msg(struct pwc_device *pdev,
 }
 
 static int set_video_mode_Nala(struct pwc_device *pdev, int size, int pixfmt,
-			       int frames, int *compression)
+			       int frames, int *compression, int send_to_cam)
 {
 	unsigned char buf[3];
-	int ret, fps;
+	int fps, ret = 0;
 	struct Nala_table_entry *pEntry;
 	int frames2frames[31] =
 	{ /* closest match of framerate */
@@ -207,7 +207,8 @@ static int set_video_mode_Nala(struct pwc_device *pdev, int size, int pixfmt,
 		return -EINVAL;
 
 	memcpy(buf, pEntry->mode, 3);
-	ret = send_video_command(pdev, pdev->vendpoint, buf, 3);
+	if (send_to_cam)
+		ret = send_video_command(pdev, pdev->vendpoint, buf, 3);
 	if (ret < 0) {
 		PWC_DEBUG_MODULE("Failed to send video command... %d\n", ret);
 		return ret;
@@ -246,11 +247,11 @@ static int set_video_mode_Nala(struct pwc_device *pdev, int size, int pixfmt,
 
 
 static int set_video_mode_Timon(struct pwc_device *pdev, int size, int pixfmt,
-				int frames, int *compression)
+				int frames, int *compression, int send_to_cam)
 {
 	unsigned char buf[13];
 	const struct Timon_table_entry *pChoose;
-	int ret, fps;
+	int fps, ret = 0;
 
 	if (size >= PSZ_MAX || *compression < 0 || *compression > 3)
 		return -EINVAL;
@@ -274,7 +275,8 @@ static int set_video_mode_Timon(struct pwc_device *pdev, int size, int pixfmt,
 		return -ENOENT; /* Not supported. */
 
 	memcpy(buf, pChoose->mode, 13);
-	ret = send_video_command(pdev, pdev->vendpoint, buf, 13);
+	if (send_to_cam)
+		ret = send_video_command(pdev, pdev->vendpoint, buf, 13);
 	if (ret < 0)
 		return ret;
 
@@ -300,10 +302,10 @@ static int set_video_mode_Timon(struct pwc_device *pdev, int size, int pixfmt,
 
 
 static int set_video_mode_Kiara(struct pwc_device *pdev, int size, int pixfmt,
-				int frames, int *compression)
+				int frames, int *compression, int send_to_cam)
 {
 	const struct Kiara_table_entry *pChoose = NULL;
-	int fps, ret;
+	int fps, ret = 0;
 	unsigned char buf[12];
 
 	if (size >= PSZ_MAX || *compression < 0 || *compression > 3)
@@ -332,7 +334,8 @@ static int set_video_mode_Kiara(struct pwc_device *pdev, int size, int pixfmt,
 	memcpy(buf, pChoose->mode, 12);
 
 	/* Firmware bug: video endpoint is 5, but commands are sent to endpoint 4 */
-	ret = send_video_command(pdev, 4 /* pdev->vendpoint */, buf, 12);
+	if (send_to_cam)
+		ret = send_video_command(pdev, 4, buf, 12);
 	if (ret < 0)
 		return ret;
 
@@ -358,7 +361,7 @@ static int set_video_mode_Kiara(struct pwc_device *pdev, int size, int pixfmt,
 }
 
 int pwc_set_video_mode(struct pwc_device *pdev, int width, int height,
-	int pixfmt, int frames, int *compression)
+	int pixfmt, int frames, int *compression, int send_to_cam)
 {
 	int ret, size;
 
@@ -369,13 +372,13 @@ int pwc_set_video_mode(struct pwc_device *pdev, int width, int height,
 
 	if (DEVICE_USE_CODEC1(pdev->type)) {
 		ret = set_video_mode_Nala(pdev, size, pixfmt, frames,
-					  compression);
+					  compression, send_to_cam);
 	} else if (DEVICE_USE_CODEC3(pdev->type)) {
 		ret = set_video_mode_Kiara(pdev, size, pixfmt, frames,
-					   compression);
+					   compression, send_to_cam);
 	} else {
 		ret = set_video_mode_Timon(pdev, size, pixfmt, frames,
-					   compression);
+					   compression, send_to_cam);
 	}
 	if (ret < 0) {
 		PWC_ERROR("Failed to set video mode %s@%d fps; return code = %d\n", size2name[size], frames, ret);

drivers/media/video/pwc/pwc-if.c

@@ -385,8 +385,8 @@ static int pwc_isoc_init(struct pwc_device *pdev)
 retry:
 	/* We first try with low compression and then retry with a higher
 	   compression setting if there is not enough bandwidth. */
-	ret = pwc_set_video_mode(pdev, pdev->width, pdev->height,
-				 pdev->pixfmt, pdev->vframes, &compression);
+	ret = pwc_set_video_mode(pdev, pdev->width, pdev->height, pdev->pixfmt,
+				 pdev->vframes, &compression, 1);
 
 	/* Get the current alternate interface, adjust packet size */
 	intf = usb_ifnum_to_if(udev, 0);
@@ -1129,7 +1129,7 @@ static int usb_pwc_probe(struct usb_interface *intf, const struct usb_device_id
 
 	/* Setup intial videomode */
 	rc = pwc_set_video_mode(pdev, MAX_WIDTH, MAX_HEIGHT,
-				V4L2_PIX_FMT_YUV420, 30, &compression);
+				V4L2_PIX_FMT_YUV420, 30, &compression, 1);
 	if (rc)
 		goto err_free_mem;
 

drivers/media/video/pwc/pwc-v4l.c

@@ -493,7 +493,7 @@ static int pwc_s_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *f)
 			(pixelformat>>24)&255);
 
 	ret = pwc_set_video_mode(pdev, f->fmt.pix.width, f->fmt.pix.height,
-				 pixelformat, 30, &compression);
+				 pixelformat, 30, &compression, 0);
 
 	PWC_DEBUG_IOCTL("pwc_set_video_mode(), return=%d\n", ret);
 
@@ -1137,7 +1137,7 @@ static int pwc_s_parm(struct file *file, void *fh,
 	}
 
 	ret = pwc_set_video_mode(pdev, pdev->width, pdev->height, pdev->pixfmt,
-				 fps, &compression);
+				 fps, &compression, 0);
 
 	pwc_g_parm(file, fh, parm);
 

drivers/media/video/pwc/pwc.h

@@ -369,7 +369,7 @@ void pwc_construct(struct pwc_device *pdev);
 /** Functions in pwc-ctrl.c */
 /* Request a certain video mode. Returns < 0 if not possible */
 extern int pwc_set_video_mode(struct pwc_device *pdev, int width, int height,
-			      int pixfmt, int frames, int *compression);
+	int pixfmt, int frames, int *compression, int send_to_cam);
 extern unsigned int pwc_get_fps(struct pwc_device *pdev, unsigned int index, unsigned int size);
 extern int pwc_set_leds(struct pwc_device *pdev, int on_value, int off_value);
 extern int pwc_get_cmos_sensor(struct pwc_device *pdev, int *sensor);