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

Adam Ford
2022-04-11T12:24:25Z

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