Re: [PATCH 04/11] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()

From: Adam Ford <aford173@gmail.com>
To: Jagan Teki <jagan@amarulasolutions.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>,
	Inki Dae <inki.dae@samsung.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Joonyoung Shim <jy0922.shim@samsung.com>,
	Seung-Woo Kim <sw0312.kim@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Frieder Schrempf <frieder.schrempf@kontron.de>,
	Fancy Fang <chen.fang@nxp.com>,
	Tim Harvey <tharvey@gateworks.com>,
	Michael Nazzareno Trimarchi <michael@amarulasolutions.com>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Robert Foss <robert.foss@linaro.org>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Rob Herring <robh+dt@kernel.org>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	devicetree <devicetree@vger.kernel.org>,
	linux-samsung-soc <linux-samsung-soc@vger.kernel.org>,
	arm-soc <linux-arm-kernel@lists.infradead.org>,
	NXP Linux Team <linux-imx@nxp.com>,
	linux-amarula <linux-amarula@amarulasolutions.com>
Subject: Re: [PATCH 04/11] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()
Date: Mon, 11 Apr 2022 07:23:06 -0500	[thread overview]
Message-ID: <CAHCN7xJmiEBsbZRepsM0FLd8YDSQj8GUwwyYm4M_ViJFPoU8FQ@mail.gmail.com> (raw)
In-Reply-To: <20220408162108.184583-5-jagan@amarulasolutions.com>

On Fri, Apr 8, 2022 at 11:22 AM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> Host transfer() in DSI master will invoke only when the DSI commands
> are sent from DSI devices like DSI Panel or DSI bridges and this
> host transfer wouldn't invoke for I2C-based-DSI bridge drivers.
>
> Handling DSI host initialization in transfer calls misses the
> controller setup for I2C configured DSI bridges.
>
> This patch adds the DSI initialization from transfer to bridge
> pre_enable as the bridge pre_enable API is invoked by core as
> it is common across all classes of DSI device drivers.
>
> v1:
> * keep DSI init in host transfer
>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>  drivers/gpu/drm/bridge/samsung-dsim.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index ff05c8e01cff..3e12b469dfa8 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -1290,6 +1290,13 @@ static void samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge,
>         }
>
>         dsi->state |= DSIM_STATE_ENABLED;
> +
> +       if (!(dsi->state & DSIM_STATE_INITIALIZED)) {
> +               ret = samsung_dsim_init(dsi);
> +               if (ret)
> +                       return;
> +               dsi->state |= DSIM_STATE_INITIALIZED;

Out of curiosity, is there a reason that  dsi->state cannot add
DSIM_STATE_INITIALIZED inside the samsung_dsim_init function call?  It
seems to me that if samsung_dsim_init returns successfully, it should
set that flag.  I don't know if it's called from other places or not.

adam
> +       }
>  }
>
>  static void samsung_dsim_atomic_enable(struct drm_bridge *bridge,
> --
> 2.25.1
>