V4L/DVB: V4L2: Replace loops for finding max buffers in VIDIOC_REQBUFS callbacks

Due to obvious copy and paste coding a number of video capture drivers
which implement a limit on the buffer memory decremented the user
supplied buffer count in a while loop until it reaches an acceptable
value.

This is a silly thing to do when the maximum value can be directly
computed.

Signed-off-by: Andreas Bombe <aeb@debian.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/bt8xx/bttv-driver.c

@@ -1806,8 +1806,8 @@ buffer_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
 	*size = fh->fmt->depth*fh->width*fh->height >> 3;
 	if (0 == *count)
 		*count = gbuffers;
-	while (*size * *count > gbuffers * gbufsize)
-		(*count)--;
+	if (*size * *count > gbuffers * gbufsize)
+		*count = (gbuffers * gbufsize) / *size;
 	return 0;
 }
 

drivers/media/video/cx23885/cx23885-video.c

@@ -514,8 +514,8 @@ static int buffer_setup(struct videobuf_queue *q, unsigned int *count,
 	*size = fh->fmt->depth*fh->width*fh->height >> 3;
 	if (0 == *count)
 		*count = 32;
-	while (*size * *count > vid_limit * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > vid_limit * 1024 * 1024)
+		*count = (vid_limit * 1024 * 1024) / *size;
 	return 0;
 }
 

drivers/media/video/cx88/cx88-video.c

@@ -561,8 +561,8 @@ buffer_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
 	*size = fh->fmt->depth*fh->width*fh->height >> 3;
 	if (0 == *count)
 		*count = 32;
-	while (*size * *count > vid_limit * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > vid_limit * 1024 * 1024)
+		*count = (vid_limit * 1024 * 1024) / *size;
 	return 0;
 }
 

drivers/media/video/mx1_camera.c

@@ -139,8 +139,8 @@ static int mx1_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
 	if (!*count)
 		*count = 32;
 
-	while (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
+		*count = (MAX_VIDEO_MEM * 1024 * 1024) / *size;
 
 	dev_dbg(icd->dev.parent, "count=%d, size=%d\n", *count, *size);
 

drivers/media/video/omap24xxcam.c

@@ -452,8 +452,8 @@ static int omap24xxcam_vbq_setup(struct videobuf_queue *vbq, unsigned int *cnt,
 	*size = fh->pix.sizeimage;
 
 	/* accessing fh->cam->capture_mem is ok, it's constant */
-	while (*size * *cnt > fh->cam->capture_mem)
-		(*cnt)--;
+	if (*size * *cnt > fh->cam->capture_mem)
+		*cnt = fh->cam->capture_mem / *size;
 
 	return 0;
 }

drivers/media/video/pxa_camera.c

@@ -253,8 +253,8 @@ static int pxa_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
 
 	if (0 == *count)
 		*count = 32;
-	while (*size * *count > vid_limit * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > vid_limit * 1024 * 1024)
+		*count = (vid_limit * 1024 * 1024) / *size;
 
 	return 0;
 }

drivers/media/video/s2255drv.c

@@ -702,8 +702,8 @@ static int buffer_setup(struct videobuf_queue *vq, unsigned int *count,
 	if (0 == *count)
 		*count = S2255_DEF_BUFS;
 
-	while (*size * (*count) > vid_limit * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > vid_limit * 1024 * 1024)
+		*count = (vid_limit * 1024 * 1024) / *size;
 
 	return 0;
 }

drivers/media/video/sh_mobile_ceu_camera.c

@@ -213,8 +213,8 @@ static int sh_mobile_ceu_videobuf_setup(struct videobuf_queue *vq,
 		*count = 2;
 
 	if (pcdev->video_limit) {
-		while (PAGE_ALIGN(*size) * *count > pcdev->video_limit)
-			(*count)--;
+		if (PAGE_ALIGN(*size) * *count > pcdev->video_limit)
+			*count = pcdev->video_limit / PAGE_ALIGN(*size);
 	}
 
 	dev_dbg(icd->dev.parent, "count=%d, size=%d\n", *count, *size);

drivers/media/video/vivi.c

@@ -749,8 +749,8 @@ buffer_setup(struct videobuf_queue *vq, unsigned int *count, unsigned int *size)
 	if (0 == *count)
 		*count = 32;
 
-	while (*size * *count > vid_limit * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > vid_limit * 1024 * 1024)
+		*count = (vid_limit * 1024 * 1024) / *size;
 
 	dprintk(dev, 1, "%s, count=%d, size=%d\n", __func__,
 		*count, *size);

drivers/media/video/zr364xx.c

@@ -376,8 +376,8 @@ static int buffer_setup(struct videobuf_queue *vq, unsigned int *count,
 	if (*count == 0)
 		*count = ZR364XX_DEF_BUFS;
 
-	while (*size * (*count) > ZR364XX_DEF_BUFS * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > ZR364XX_DEF_BUFS * 1024 * 1024)
+		*count = (ZR364XX_DEF_BUFS * 1024 * 1024) / *size;
 
 	return 0;
 }

drivers/staging/cx25821/cx25821-video.c

@@ -516,8 +516,8 @@ int cx25821_buffer_setup(struct videobuf_queue *q, unsigned int *count,
 	if (0 == *count)
 		*count = 32;
 
-	while (*size * *count > vid_limit * 1024 * 1024)
-		(*count)--;
+	if (*size * *count > vid_limit * 1024 * 1024)
+		*count = (vid_limit * 1024 * 1024) / *size;
 
 	return 0;
 }