linux-kernel - Re: [PATCH] drm: bridge: samsung-dsim: Don't use FORCE_STOP

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Date: Tue, 30 Jan 2024 10:11:55 +0100
From: Dario Binacchi <dario.binacchi@...rulasolutions.com>
To: Michael Walle <mwalle@...nel.org>
Cc: Dave Airlie <airlied@...il.com>, Dmitry Osipenko <dmitry.osipenko@...labora.com>, 
	Inki Dae <daeinki@...il.com>, Neil Armstrong <neil.armstrong@...aro.org>, 
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>, Robert Foss <rfoss@...nel.org>, 
	Frieder Schrempf <frieder.schrempf@...tron.de>, Jagan Teki <jagan@...rulasolutions.com>, 
	Andrzej Hajda <andrzej.hajda@...el.com>, Marek Szyprowski <m.szyprowski@...sung.com>, 
	Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>, 
	Tim Harvey <tharvey@...eworks.com>, Alexander Stein <alexander.stein@...tq-group.com>, 
	linux-kernel@...r.kernel.org, 
	DRI mailing list <dri-devel@...ts.freedesktop.org>, Daniel Vetter <daniel@...ll.ch>, 
	Michael Trimarchi <michael@...rulasolutions.com>
Subject: Re: [PATCH] drm: bridge: samsung-dsim: Don't use FORCE_STOP_STATE

Hi Michael,

On Mon, Jan 29, 2024 at 5:06 PM Michael Walle <mwalle@...nel.org> wrote:
>
> >> Just FYI this conflictted pretty heavily with drm-misc-next changes in
> >> the same area, someone should check drm-tip has the correct
> >> resolution, I'm not really sure what is definitely should be.
> >
> > FWIW, this looks rather messy now. The drm-tip doesn't build.
> >
> > There was a new call to samsung_dsim_set_stop_state() introduced
> > in commit b2fe2292624ac (drm: bridge: samsung-dsim: enter display
> > mode in the enable() callback).
>
> I had a closer look at the latest linux-next (where somehow my patch
> made it into) and tried to apply commit b2fe2292624ac (drm: bridge:
> samsung-dsim: enter display mode in the enable() callback). It looks
> like only the following hunk is still needed from that patch. Everything
> else is covered by this fixes patch.
>
> Dario, could you rebase your commit onto this patch? I had a quick test
> with this change and it seems to work fine for our case.
>
> --snip--
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c
> b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 63a1a0c88be4..92755c90e7d2 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -1498,6 +1498,8 @@ static void samsung_dsim_atomic_disable(struct
> drm_bridge *bridge,
>          if (!(dsi->state & DSIM_STATE_ENABLED))
>                  return;
>
> +       samsung_dsim_set_display_enable(dsi, false);
> +
>          dsi->state &= ~DSIM_STATE_VIDOUT_AVAILABLE;
>   }
>
> @@ -1506,8 +1508,6 @@ static void
> samsung_dsim_atomic_post_disable(struct drm_bridge *bridge,
>   {
>          struct samsung_dsim *dsi = bridge_to_dsi(bridge);
>
> -       samsung_dsim_set_display_enable(dsi, false);
> -
>          dsi->state &= ~DSIM_STATE_ENABLED;
>          pm_runtime_put_sync(dsi->dev);
>   }
> --snip--
>
> -michael

I'm sorry, but I didn't understand well what I have to do.
This is what I have done:

git clone https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
cd linux-next
# add your changes, the ones of the emails
git am --reject 0001-drm-bridge-samsung-dsim-enter-display-mode-in-the-en.patch

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c
b/drivers/gpu/drm/bridge/samsung-dsim.c
index 92755c90e7d2..b47929072583 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1508,6 +1508,9 @@ static void
samsung_dsim_atomic_post_disable(struct drm_bridge *bridge,
 {
        struct samsung_dsim *dsi = bridge_to_dsi(bridge);

+       if (!samsung_dsim_hw_is_exynos(dsi->plat_data->hw_type))
+               samsung_dsim_set_stop_state(dsi, true);
+
        dsi->state &= ~DSIM_STATE_ENABLED;
        pm_runtime_put_sync(dsi->dev);
 }

And then test the driver for my use case.

Is everything I wrote correct, or am I making a mistake?

Thanks and regards,
Dario

-- 

Dario Binacchi

Senior Embedded Linux Developer

dario.binacchi@...rulasolutions.com

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