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Date: Thu, 10 Oct 2024 07:43:08 +0200
From: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <linux@weissschuh.net>
To: Harry Wentland <harry.wentland@amd.com>, Leo Li <sunpeng.li@amd.com>
Cc: Mario Limonciello <mario.limonciello@amd.com>, 
	amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, 
	Dustin Howett <dustin@howett.net>, linux-doc@vger.kernel.org, 
	Alex Deucher <alexander.deucher@amd.com>, Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>, 
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, 
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
	Thomas Zimmermann <tzimmermann@suse.de>, Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>, 
	Matt Hartley <matt.hartley@gmail.com>, Kieran Levin <ktl@framework.net>, 
	Hans de Goede <hdegoede@redhat.com>, Jani Nikula <jani.nikula@linux.intel.com>, 
	Xinhui Pan <Xinhui.Pan@amd.com>, Jonathan Corbet <corbet@lwn.net>
Subject: Re: [PATCH v6 2/4] drm/amd/display: Add support for minimum
 backlight quirk
Message-ID: <bf61e7f2-9324-495d-af68-4b38ec211eee@t-8ch.de>
References: <20240824-amdgpu-min-backlight-quirk-v6-0-1ed776a17fb3@weissschuh.net>
 <20240824-amdgpu-min-backlight-quirk-v6-2-1ed776a17fb3@weissschuh.net>
 <1396eead-b584-4b36-b9b2-18ef783cfdbf@amd.com>
 <9dfc1548-7e11-44c3-ba7d-4e5ff7965a66@amd.com>
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In-Reply-To: <9dfc1548-7e11-44c3-ba7d-4e5ff7965a66@amd.com>

On 2024-09-16 15:43:35-0400, Harry Wentland wrote:
> On 2024-08-26 12:57, Mario Limonciello wrote:
> > On 8/24/2024 13:33, Thomas Weißschuh wrote:
> >> Not all platforms provide the full range of PWM backlight capabilities
> >> supported by the hardware through ATIF.
> >> Use the generic drm panel minimum backlight quirk infrastructure to
> >> override the capabilities where necessary.
> >>
> >> Testing the backlight quirk together with the "panel_power_savings"
> >> sysfs file has not shown any negative impact.
> >> One quirk seems to be that 0% at panel_power_savings=0 seems to be
> >> slightly darker than at panel_power_savings=4.
> > 
> > Thanks; This is the kind of thing I was worried about.
> > 
> > Harry, Leo,
> > 
> > Is that expected?  I wonder if we need to internally turn off panel
> > power savings in display code when brightness falls a threshold (12
> > IIRC was the real "minimum" advertised in the table?).
> 
> How much darker? Is it bothersome?

Was this questions for meant for me?
To me personally it's absolutely not bothersome.
I probably wouldn't have noticed it if not explicitly looking for it.

> I wonder the FW and driver have different min backlight values now.
> 
> Leo, any thoughts?

Friendly ping.