From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jani Nikula <jani.nikula@linux.intel.com>
Subject: Re: [PATCH] drm/panel: lvds: Handle the optional regulator case properly
Date: Thu, 11 Jan 2018 16:31:59 +0200
Message-ID: <87zi5kii00.fsf@intel.com>
References: <20180110155941.16109-1-maxime.ripard@free-electrons.com> <1944741.zEkzsdPTSS@avalon>
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To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>, Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>, Sean Paul <seanpaul@chromium.org>, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Mark Brown <broonie@kernel.org>
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On Thu, 11 Jan 2018, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
> My preference, however, would be for devm_regulator_get_optional() to return 
> NULL when no regulator is present. The current implementation returns -ENODEV 
> in multiple cases, making it impossible to properly discriminate between 
> having no regulator and not being able to get the regulator due to an error.

Just a word of warning, IS_ERR(NULL) is false, and your proposed change
would apparently require quite a churn all over the kernel.

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Technology Center