Re: [PATCH v3] vsp1: fix video output on R8A77970

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Sergei,

Thank you for the patch.

On Thursday, 18 January 2018 16:05:51 EET Sergei Shtylyov wrote:
> Commit d455b45f8393 ("v4l: vsp1: Add support for new VSP2-BS, VSP2-DL,
> and VSP2-D instances") added support for the VSP2-D found in the R-Car
> V3M (R8A77970) but the video output that VSP2-D sends to DU has a greenish
> garbage-like line repeated every 8 screen rows. It turns out that R-Car
> V3M has the LIF0 buffer attribute register that you need to set to a non-
> default value in order to get rid of the output artifacts...
> 
> Based on the original (and large) patch by Daisuke Matsushita
> <daisuke.matsushita.ns@hitachi.com>.
> 
> Fixes: d455b45f8393 ("v4l: vsp1: Add support for new VSP2-BS, VSP2-DL and
> VSP2-D instances") Signed-off-by: Sergei Shtylyov
> <sergei.shtylyov@cogentembedded.com>
> 
> ---
> This patch is against the 'media_tree.git' repo's 'fixes' branch.
> 
> Changes in version 3:
> - reworded the comment in lif_configure();
> - reworded the patch description.
> 
> Changes in version 2:
> - added a  comment before the V3M SoC check;
> - fixed indetation in that check;
> - reformatted  the patch description.
> 
>  drivers/media/platform/vsp1/vsp1_lif.c  |   15 +++++++++++++++
>  drivers/media/platform/vsp1/vsp1_regs.h |    5 +++++
>  2 files changed, 20 insertions(+)
> 
> Index: media_tree/drivers/media/platform/vsp1/vsp1_lif.c
> ===================================================================
> --- media_tree.orig/drivers/media/platform/vsp1/vsp1_lif.c
> +++ media_tree/drivers/media/platform/vsp1/vsp1_lif.c
> @@ -155,6 +155,21 @@ static void lif_configure(struct vsp1_en
>  			(obth << VI6_LIF_CTRL_OBTH_SHIFT) |
>  			(format->code == 0 ? VI6_LIF_CTRL_CFMT : 0) |
>  			VI6_LIF_CTRL_REQSEL | VI6_LIF_CTRL_LIF_EN);
> +
> +	/*
> +	 * On R-Car V3M the LIF0 buffer attribute register has to be set
> +	 * to a non-default value to guarantee proper operation (otherwise
> +	 * artifacts may appear on the output). The value required by
> +	 * the manual is not explained but is likely a buffer size or
> +	 * threshold...

One period is enough :-)

> +	 */
> +	if ((entity->vsp1->version &
> +	     (VI6_IP_VERSION_MODEL_MASK | VI6_IP_VERSION_SOC_MASK)) ==
> +	    (VI6_IP_VERSION_MODEL_VSPD_V3 | VI6_IP_VERSION_SOC_V3M)) {
> +		vsp1_lif_write(lif, dl, VI6_LIF_LBA,
> +			       VI6_LIF_LBA_LBA0 |
> +			       (1536 << VI6_LIF_LBA_LBA1_SHIFT));
> +	}

There's no need for braces or inner parentheses. To make this easier to read I 
propose defining a new macro VI6_IP_VERSION_MASK that combines both the model 
and SoC. Otherwise this looks good to me,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

I'll post a v4 with that change in reply to this e-mail, please let me know if 
you're fine with it.

>  }
> 
>  static const struct vsp1_entity_operations lif_entity_ops = {
> Index: media_tree/drivers/media/platform/vsp1/vsp1_regs.h
> ===================================================================
> --- media_tree.orig/drivers/media/platform/vsp1/vsp1_regs.h
> +++ media_tree/drivers/media/platform/vsp1/vsp1_regs.h
> @@ -693,6 +693,11 @@
>  #define VI6_LIF_CSBTH_LBTH_MASK		(0x7ff << 0)
>  #define VI6_LIF_CSBTH_LBTH_SHIFT	0
> 
> +#define VI6_LIF_LBA			0x3b0c
> +#define VI6_LIF_LBA_LBA0		(1 << 31)
> +#define VI6_LIF_LBA_LBA1_MASK		(0xfff << 16)
> +#define VI6_LIF_LBA_LBA1_SHIFT		16
> +
>  /* ------------------------------------------------------------------------
>   * Security Control Registers
>   */

-- 
Regards,

Laurent Pinchart