linux-kernel - Re: [PATCH v3 35/37] drm/bridge: tc358768: Stop disabling when failing to enable

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Message-ID: <dsccxyorddnhjiff37zxmwh6mwerwtlabxxp6csugomalsgfwv@mfnsky7pacha>
Date: Thu, 13 Feb 2025 18:37:11 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Maxime Ripard <mripard@...nel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Andrzej Hajda <andrzej.hajda@...el.com>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>, Jonas Karlman <jonas@...boo.se>, 
	Jernej Skrabec <jernej.skrabec@...il.com>, Douglas Anderson <dianders@...omium.org>, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 35/37] drm/bridge: tc358768: Stop disabling when
 failing to enable

On Thu, Feb 13, 2025 at 03:43:54PM +0100, Maxime Ripard wrote:
> The tc358768 bridge driver, if enabling it fails, tries to disable it.
> This is pretty uncommon in bridge drivers, and also stands in the way
> for further reworks.
> 
> Worse, since pre_enable and enable aren't expected to fail, disable and
> post_disable might be called twice: once to handle the failure, and once
> to actually disable the bridge.
> 
> Since post_disable uses regulators and clocks, this would lead to enable
> count imbalances.
> 
> In order to prevent that imbalance, and to allow further reworks, let's
> drop the calls to disable and post_disable, but keep the warning to let
> users know about what's going on.
> 
> Signed-off-by: Maxime Ripard <mripard@...nel.org>
> ---
>  drivers/gpu/drm/bridge/tc358768.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> 

-- 
With best wishes
Dmitry