Re: [PATCH v2 3/9] drm/msm/mdp4: add lcdc-align-lsb flag to control lane alignment

From: Rob Clark <robdclark@gmail.com>
To: Jonathan <jonathan@marek.ca>
Cc: freedreno <freedreno@lists.freedesktop.org>,
	Chris Healy <Chris.Healy@zii.aero>,
	Fabio Estevam <festevam@gmail.com>,
	David Airlie <airlied@linux.ie>,
	boris.brezillon@bootlin.com, Thierry Reding <treding@nvidia.com>,
	Sean Paul <seanpaul@chromium.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 3/9] drm/msm/mdp4: add lcdc-align-lsb flag to control lane alignment
Date: Sun, 2 Dec 2018 10:49:44 -0500	[thread overview]
Message-ID: <CAF6AEGujMhgArNPq9SXwGhu3KT_fW770qBKyXBD2=oA6pghJyA@mail.gmail.com> (raw)
In-Reply-To: <20181122015237.14534-3-jonathan@marek.ca>

On Wed, Nov 21, 2018 at 8:55 PM Jonathan Marek <jonathan@marek.ca> wrote:
>
> Controls which of the 8 lanes are used for 6 bit color.
>
> Signed-off-by: Jonathan Marek <jonathan@marek.ca>
> ---
>  .../gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c | 22 ++++++++++++-------
>  1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
> index e19ab2ab63f7..7d8d11c8150a 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
> @@ -377,20 +377,26 @@ static void mdp4_lcdc_encoder_enable(struct drm_encoder *encoder)
>         unsigned long pc = mdp4_lcdc_encoder->pixclock;
>         struct mdp4_kms *mdp4_kms = get_kms(encoder);
>         struct drm_panel *panel;
> +       uint32_t config;
>         int i, ret;
>
>         if (WARN_ON(mdp4_lcdc_encoder->enabled))
>                 return;
>
>         /* TODO: hard-coded for 18bpp: */
> -       mdp4_crtc_set_config(encoder->crtc,
> -                       MDP4_DMA_CONFIG_R_BPC(BPC6) |
> -                       MDP4_DMA_CONFIG_G_BPC(BPC6) |
> -                       MDP4_DMA_CONFIG_B_BPC(BPC6) |
> -                       MDP4_DMA_CONFIG_PACK_ALIGN_MSB |
> -                       MDP4_DMA_CONFIG_PACK(0x21) |
> -                       MDP4_DMA_CONFIG_DEFLKR_EN |
> -                       MDP4_DMA_CONFIG_DITHER_EN);
> +       config =
> +               MDP4_DMA_CONFIG_R_BPC(BPC6) |
> +               MDP4_DMA_CONFIG_G_BPC(BPC6) |
> +               MDP4_DMA_CONFIG_B_BPC(BPC6) |
> +               MDP4_DMA_CONFIG_PACK(0x21) |
> +               MDP4_DMA_CONFIG_DEFLKR_EN |
> +               MDP4_DMA_CONFIG_DITHER_EN;
> +
> +       if (!of_find_property(dev->dev->of_node, "lcdc-align-lsb", NULL))
> +               config |= MDP4_DMA_CONFIG_PACK_ALIGN_MSB;
> +
> +

looks reasonable, except extra newline (minor nit) and more
importantly the new dt property needs to be documented (and cc'd to
devicetree list)

BR,
-R

> +       mdp4_crtc_set_config(encoder->crtc, config);
>         mdp4_crtc_set_intf(encoder->crtc, INTF_LCDC_DTV, 0);
>
>         bs_set(mdp4_lcdc_encoder, 1);
> --
> 2.17.1
>