[PATCHv2,1/1] media: imx: Round line size to 4 bytes

Commit Message

Dorota Czaplejewicz Sept. 14, 2022, 3:32 p.m. UTC

Section 13.7.6.13 "CSI Image Parameter Register" of the
i.MX 8M Quad Applications Processors Reference Manual
states that the line size should be divisible by 8 bytes.
However, the hardware also accepts sizes divisible by 4 bytes,
which are needed to fully utilize the S5K3L6XX sensors.

This patch accepts line sizes divisible 4-bytes in non-planar mode.

---
Hello,

the Librem 5 is using an out-of-tree driver for s5k3l6xx, and rounding to 4 is optimal to operate it.

Please ignore my previous series, I sent it by mistake.

Cheers,
Dorota Czaplejewicz

 drivers/staging/media/imx/imx7-media-csi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Dan Carpenter Sept. 14, 2022, 3:45 p.m. UTC | #1

On Wed, Sep 14, 2022 at 05:32:36PM +0200, Dorota Czaplejewicz wrote:
> Section 13.7.6.13 "CSI Image Parameter Register" of the
> i.MX 8M Quad Applications Processors Reference Manual
> states that the line size should be divisible by 8 bytes.
> However, the hardware also accepts sizes divisible by 4 bytes,
> which are needed to fully utilize the S5K3L6XX sensors.
> 
> This patch accepts line sizes divisible 4-bytes in non-planar mode.
> 
> ---

So do we need a Fixes tag?  Was this ever working in kernel?

Definitely need a Signed-off-by line, though. ;)

regards,
dan carpenter

Dorota Czaplejewicz Sept. 14, 2022, 4:09 p.m. UTC | #2

On Wed, 14 Sep 2022 18:45:05 +0300
Dan Carpenter <[e-mail]> wrote:

> On Wed, Sep 14, 2022 at 05:32:36PM +0200, Dorota Czaplejewicz wrote:
> > Section 13.7.6.13 "CSI Image Parameter Register" of the
> > i.MX 8M Quad Applications Processors Reference Manual
> > states that the line size should be divisible by 8 bytes.
> > However, the hardware also accepts sizes divisible by 4 bytes,
> > which are needed to fully utilize the S5K3L6XX sensors.
> > 
> > This patch accepts line sizes divisible 4-bytes in non-planar mode.
> > 
> > ---  
> 
> So do we need a Fixes tag?  Was this ever working in kernel?
> 
No, it wasn't actually ever working upstream, just in a patched up branch I mixed up with the real thing.
> Definitely need a Signed-off-by line, though. ;)

Thanks again!
--Dorota
> 
> regards,
> dan carpenter
>

Patch

diff --git a/drivers/staging/media/imx/imx7-media-csi.c b/drivers/staging/media/imx/imx7-media-csi.c
index a0553c24cce4..af821b410c3f 100644
--- a/drivers/staging/media/imx/imx7-media-csi.c
+++ b/drivers/staging/media/imx/imx7-media-csi.c
@@ -999,10 +999,10 @@  static int imx7_csi_mbus_fmt_to_pix_fmt(struct v4l2_pix_format *pix,
 	}
 
 	/* Round up width for minimum burst size */
-	width = round_up(mbus->width, 8);
+	width = round_up(mbus->width, 4);
 
 	/* Round up stride for IDMAC line start address alignment */
-	stride = round_up((width * cc->bpp) >> 3, 8);
+	stride = round_up((width * cc->bpp) >> 3, 4);
 
 	pix->width = width;
 	pix->height = mbus->height;