[PATCH V2 26/29] staging: bcm2835-camera: Fix stride on RGB3/BGR3 formats

Stefan Wahren wahrenst at gmx.net
Sat Jun 29 19:31:40 UTC 2019


From: Dave Stevenson <dave.stevenson at raspberrypi.org>

RGB3/BGR3 end up being 3 bytes per pixel, which meant that
the alignment code ended up trying to align using bitmasking
with a mask of 96.
That doesn't work, so switch to an arithmetic alignment for
those formats.

Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.org>
Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
Acked-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung at kernel.org>
---
 .../vc04_services/bcm2835-camera/bcm2835-camera.c  | 26 +++++++++++++++++-----
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
index 1aaae57..1ad65dd 100644
--- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
@@ -960,13 +960,27 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 			      1, 0);
 	f->fmt.pix.bytesperline = f->fmt.pix.width * mfmt->ybbp;
 	if (!mfmt->remove_padding) {
-		int align_mask = ((32 * mfmt->depth) >> 3) - 1;
-		/* GPU isn't removing padding, so stride is aligned to 32 */
-		f->fmt.pix.bytesperline =
-			(f->fmt.pix.bytesperline + align_mask) & ~align_mask;
+		if (mfmt->depth == 24) {
+			/*
+			 * 24bpp is a pain as we can't use simple masking.
+			 * Min stride is width aligned to 16, times 24bpp.
+			 */
+			f->fmt.pix.bytesperline =
+				((f->fmt.pix.width + 15) & ~15) * 3;
+		} else {
+			/*
+			 * GPU isn't removing padding, so stride is aligned to
+			 * 32
+			 */
+			int align_mask = ((32 * mfmt->depth) >> 3) - 1;
+
+			f->fmt.pix.bytesperline =
+				(f->fmt.pix.bytesperline + align_mask) &
+							~align_mask;
+		}
 		v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
-			 "Not removing padding, so bytes/line = %d, (align_mask %d)\n",
-			 f->fmt.pix.bytesperline, align_mask);
+			 "Not removing padding, so bytes/line = %d\n",
+			 f->fmt.pix.bytesperline);
 	}

 	/* Image buffer has to be padded to allow for alignment, even though
--
2.7.4



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