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i.MX6 CSI: Fix MIPI camera operation in RAW/Bayer mode

PATCH In review Krzysztof Hałasa 4 participants 6 messages Oct 17, 2017

Subsystems (4)
Media (V4L/DVB) Arm i.MX and Layerscape Staging Media drivers for Freescale i.MX
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Krzysztof Hałasa

author
#0 lore raw

PATCH 1/1 i.MX6 CSI: Fix MIPI camera operation in RAW/Bayer mode

Without this fix, in 8-bit Y/Bayer mode, every other 8-byte group of pixels is lost.
Not sure about possible side effects, though.

Signed-off-by Krzysztof Hałasa <[email protected]>
drivers/staging/media/imx/imx-media-csi.c +1 -1
@@ -340,7 +340,7 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
 	case V4L2_PIX_FMT_SGBRG8:
 	case V4L2_PIX_FMT_SGRBG8:
 	case V4L2_PIX_FMT_SRGGB8:
-		burst_size = 8;
+		burst_size = 16;
 		passthrough = true;
 		passthrough_bits = 8;
 		break;
Signature · 4 lines
Krzysztof Halasa

Industrial Research Institute for Automation and Measurements PIAP
Al. Jerozolimskie 202, 02-486 Warsaw, Poland
reviewer
#1 lore raw

Hi Krzysztof,

Quoted 9 lines · Krzysztof Hałasa

Without this fix, in 8-bit Y/Bayer mode, every other 8-byte group of pixels is lost.
Not sure about possible side effects, though.

Signed-off-by Krzysztof Hałasa <[email protected]>

drivers/staging/media/imx/imx-media-csi.c static int csi_idmac_setup_channel(struct csi_priv *priv) · line 346

Quoted 8 lines
drivers/staging/media/imx/imx-media-csi.c +1 -1
@@ -340,7 +340,7 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
        case V4L2_PIX_FMT_SGBRG8:
        case V4L2_PIX_FMT_SGRBG8:
        case V4L2_PIX_FMT_SRGGB8:
-               burst_size = 8;
+               burst_size = 16;
                passthrough = true;
                passthrough_bits = 8;
                break;

Russell has sent the same fix and Philipp made a comment about the possibility of using 32-byte or 64-byte bursts:
http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-October/111960.html

author
#2 lore raw
Quoted 7 lines · Fabio Estevam
Quoted 7 lines
drivers/staging/media/imx/imx-media-csi.c +0 -1
@@ -340,7 +340,7 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
        case V4L2_PIX_FMT_SGBRG8:
        case V4L2_PIX_FMT_SGRBG8:
        case V4L2_PIX_FMT_SRGGB8:
-               burst_size = 8;
Quoted 8 lines

drivers/staging/media/imx/imx-media-csi.c static int csi_idmac_setup_channel(struct csi_priv *priv) · line 346

Quoted 4 lines
drivers/staging/media/imx/imx-media-csi.c +1 -0
+               burst_size = 16;
                passthrough = true;
                passthrough_bits = 8;
                break;

Russell has sent the same fix and Philipp made a comment about the possibility of using 32-byte or 64-byte bursts:
http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-October/111960.html

Great.

Sometimes I wonder how many people are working on exactly the same stuff.

Signature · 4 lines
Krzysztof Halasa

Industrial Research Institute for Automation and Measurements PIAP
Al. Jerozolimskie 202, 02-486 Warsaw, Poland
#3 lore raw
Quoted 18 lines · Krzysztof Hałasa
Quoted 7 lines · Fabio Estevam
Quoted 7 lines
drivers/staging/media/imx/imx-media-csi.c +0 -1
@@ -340,7 +340,7 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
        case V4L2_PIX_FMT_SGBRG8:
        case V4L2_PIX_FMT_SGRBG8:
        case V4L2_PIX_FMT_SRGGB8:
-               burst_size = 8;
Quoted 8 lines

drivers/staging/media/imx/imx-media-csi.c static int csi_idmac_setup_channel(struct csi_priv *priv) · line 346

Quoted 4 lines
drivers/staging/media/imx/imx-media-csi.c +1 -0
+               burst_size = 16;
                passthrough = true;
                passthrough_bits = 8;
                break;

Russell has sent the same fix and Philipp made a comment about the possibility of using 32-byte or 64-byte bursts:
http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-October/111960.html

Quoted 4 lines

Great.

Sometimes I wonder how many people are working on exactly the same stuff.

I do wish the patch was merged (which fixes a real problem) rather than hanging around for optimisation questions. We can always increase it in the future if it's deemed that a larger burst size is beneficial.

Signature · 3 lines
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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reviewer
#4 lore raw
Quoted 3 lines · Russell King - ARM Linux

I do wish the patch was merged (which fixes a real problem) rather than hanging around for optimisation questions. We can always increase it in the future if it's deemed that a larger burst size is beneficial.

Agreed.

maintainer
#5 lore raw
In reply to Russell King - ARM Linux
Quoted 19 lines · Russell King - ARM Linux
Quoted 18 lines · Krzysztof Hałasa
Quoted 15 lines · Fabio Estevam

drivers/staging/media/imx/imx-media-csi.c static int csi_idmac_setup_channel(struct csi_priv *priv) · line 346

Quoted 11 lines
drivers/staging/media/imx/imx-media-csi.c +1 -1
@@ -340,7 +340,7 @@ static int csi_idmac_setup_channel(struct csi_priv *priv)
        case V4L2_PIX_FMT_SGBRG8:
        case V4L2_PIX_FMT_SGRBG8:
        case V4L2_PIX_FMT_SRGGB8:
-               burst_size = 8;
+               burst_size = 16;
                passthrough = true;
                passthrough_bits = 8;
                break;

Russell has sent the same fix and Philipp made a comment about the possibility of using 32-byte or 64-byte bursts:
http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-October/111960.html

Quoted 8 lines
Quoted 4 lines

Great.

Sometimes I wonder how many people are working on exactly the same stuff.

I do wish the patch was merged (which fixes a real problem) rather than hanging around for optimisation questions. We can always increase it in the future if it's deemed that a larger burst size is beneficial.

I am sorry, that patch should have been part of last week's pull request. I'll send another one for -rc6.

regards
Philipp