Message-ID: <1506932384.9752.1.camel@pengutronix.de>
Subject: Re: [PATCH] imx-csi: fix burst size
From: Philipp Zabel <p.zabel@pengutronix.de>
To: Russell King <rmk+kernel@armlinux.org.uk>,
        Steve Longerbeam <slongerbeam@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-media@vger.kernel.org, devel@driverdev.osuosl.org
Date: Mon, 02 Oct 2017 10:19:44 +0200
In-Reply-To: <E1dy32l-0003Pb-Lv@rmk-PC.armlinux.org.uk>
References: <E1dy32l-0003Pb-Lv@rmk-PC.armlinux.org.uk>
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Sender: linux-media-owner@vger.kernel.org

Hi Russell,

On Fri, 2017-09-29 at 22:41 +0100, Russell King wrote:
> Setting a burst size of "8" doesn't work for IMX219 with 8-bit bayer,
> but a burst size of "16" does.  Fix this.

Do larger bursts work as well, if the width is divisible by the burst
length? Since the Bayer format can't pass through the IC direct path
anyway, 32-byte or 64-byte bursts may be possible.

> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
>  drivers/staging/media/imx/imx-media-csi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/imx/imx-media-csi.c
> b/drivers/staging/media/imx/imx-media-csi.c
> index 6d856118c223..e27bcdb63973 100644
> --- a/drivers/staging/media/imx/imx-media-csi.c
> +++ b/drivers/staging/media/imx/imx-media-csi.c
> @@ -341,7 +341,7 @@ 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;

regards
Philipp