Re: [PATCH 08/15] drm/sun4i: Fix polarity configuration for DW HDMI PHY

From: Maxime Ripard <maxime.ripard@bootlin.com>
To: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: wens@csie.org, airlied@linux.ie, robh+dt@kernel.org,
	mark.rutland@arm.com, mturquette@baylibre.com, sboyd@kernel.org,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org,
	linux-sunxi@googlegroups.com
Subject: Re: [PATCH 08/15] drm/sun4i: Fix polarity configuration for DW HDMI PHY
Date: Mon, 26 Feb 2018 10:39:30 +0100	[thread overview]
Message-ID: <20180226093930.mipjyr6sr35ldkw6@flea.lan> (raw)
In-Reply-To: <20180224214545.3740-9-jernej.skrabec@siol.net>

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Hi,

On Sat, Feb 24, 2018 at 10:45:38PM +0100, Jernej Skrabec wrote:
> Current polarity configuration code is cleary wrong since it compares
> same flag two times. However, even if flag name is fixed, it won't work
> well for resolutions which have one polarity positive and another
> negative.
> 
> Fix that by properly set each bit according to each polarity. Since
> those two bits are not described in any documentation, relationships
> were obtained by experimentation.
> 
> Fixes: b7c7436a5ff0 ("drm/sun4i: Implement A83T HDMI driver")
> 
> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> ---
>  drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> index e5bfcdd43ec9..f48e8b70fabe 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
> @@ -35,10 +35,11 @@ static int sun8i_hdmi_phy_config(struct dw_hdmi *hdmi, void *data,
>  	struct sun8i_hdmi_phy *phy = (struct sun8i_hdmi_phy *)data;
>  	u32 val = 0;
>  
> -	if ((mode->flags & DRM_MODE_FLAG_NHSYNC) &&
> -	    (mode->flags & DRM_MODE_FLAG_NHSYNC)) {
> -		val = 0x03;
> -	}
> +	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
> +		val |= 0x01;
> +
> +	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> +		val |= 0x02;

Can you introduce defines for those?

Thanks!
Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

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