From: Hans de Goede <hdegoede@redhat.com>
To: "Pali Rohár" <pali@kernel.org>,
"Akihiko Odaki" <akihiko.odaki@daynix.com>
Cc: linux-fbdev@vger.kernel.org, Ike Panhc <ike.pan@canonical.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
dri-devel@lists.freedesktop.org,
Azael Avalos <coproscefalo@gmail.com>,
Mattia Dongili <malattia@linux.it>,
Daniel Dadap <ddadap@nvidia.com>,
Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
Daniel Thompson <daniel.thompson@linaro.org>,
Jonathan Woithe <jwoithe@just42.net>,
Jonathan Corbet <corbet@lwn.net>, "Lee, Chun-Yi" <jlee@suse.com>,
Helge Deller <deller@gmx.de>, Lee Jones <lee@kernel.org>,
Robert Moore <robert.moore@intel.com>,
linux-acpi@vger.kernel.org,
Cezary Jackiewicz <cezary.jackiewicz@gmail.com>,
Len Brown <lenb@kernel.org>,
Matthew Garrett <mjg59@srcf.ucam.org>,
Kenneth Chan <kenneth.t.chan@gmail.com>,
Corentin Chary <corentin.chary@gmail.com>,
intel-gfx@lists.freedesktop.org,
acpi4asus-user@lists.sourceforge.net,
Mark Gross <markgross@kernel.org>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
platform-driver-x86@vger.kernel.org, devel@acpica.org,
Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
ibm-acpi-devel@lists.sourceforge.net,
Jingoo Han <jingoohan1@gmail.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Thomas Zimmermann <tzimmermann@suse.de>
Subject: Re: [PATCH 00/22] Fallback to native backlight
Date: Mon, 24 Oct 2022 15:23:46 +0200 [thread overview]
Message-ID: <84d86b61-7694-2e22-3593-b11b3ce33cf8@redhat.com> (raw)
In-Reply-To: <20221024131451.lvkesdg3kvyvbi7n@pali>
Hi,
On 10/24/22 15:14, Pali Rohár wrote:
> On Monday 24 October 2022 21:58:57 Akihiko Odaki wrote:
>> Regarding the second limitation, I don't even understand the difference
>> between vendor and native. My guess is that a vendor backlight device uses
>> vendor-specific ACPI interface, and a native one directly uses hardware
>> registers. If my guess is correct, the difference between vendor and native
>> does not imply that both of them are likely to exist at the same time. As
>> the conclusion, there is no more motivation to try to de-duplicate the
>> vendor/native combination than to try to de-duplicate combination of devices
>> with a single type.
>
> Hello! I just want to point one thing. On some Dell laptops there are
> 3 different ways (= 3 different APIs) how to control display backlight.
> There is ACPI driver (uses ACPI), GPU/DRM driver (i915.ko; uses directly
> HW) and platform vendor driver (dell-laptop.ko; uses vendor BIOS or
> firmware API).
Right and that is just one example of laptops which can register both
vendor + native backlight devices, which is why this whole series is
a bad idea.
Regards,
Hans
> Just every driver has different pre-calculated scaling
> values. So sometimes user wants to choose different driver just because
> it allows to set backlight level with "better" granularity. Registering
> all 3 device drivers is bad as user does not want to see 3 display
> panels and forcing registration of specific one without runtime option
> is also bad (some of those drivers do not have to be suitable or has
> worse granularity as other).
WARNING: multiple messages have this Message-ID (diff)
From: Hans de Goede <hdegoede@redhat.com>
To: "Pali Rohár" <pali@kernel.org>,
"Akihiko Odaki" <akihiko.odaki@daynix.com>
Cc: linux-fbdev@vger.kernel.org, Ike Panhc <ike.pan@canonical.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
dri-devel@lists.freedesktop.org,
Azael Avalos <coproscefalo@gmail.com>,
Mattia Dongili <malattia@linux.it>,
Daniel Dadap <ddadap@nvidia.com>,
Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
David Airlie <airlied@gmail.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
Jonathan Woithe <jwoithe@just42.net>,
Jonathan Corbet <corbet@lwn.net>, "Lee, Chun-Yi" <jlee@suse.com>,
Helge Deller <deller@gmx.de>, Lee Jones <lee@kernel.org>,
Robert Moore <robert.moore@intel.com>,
linux-acpi@vger.kernel.org,
Cezary Jackiewicz <cezary.jackiewicz@gmail.com>,
Len Brown <lenb@kernel.org>,
Kenneth Chan <kenneth.t.chan@gmail.com>,
Corentin Chary <corentin.chary@gmail.com>,
intel-gfx@lists.freedesktop.org,
acpi4asus-user@lists.sourceforge.net,
Maxime Ripard <mripard@kernel.org>,
Mark Gross <markgross@kernel.org>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Daniel Vetter <daniel@ffwll.ch>,
platform-driver-x86@vger.kernel.org, devel@acpica.org,
ibm-acpi-devel@lists.sourceforge.net,
Jingoo Han <jingoohan1@gmail.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Thomas Zimmermann <tzimmermann@suse.de>
Subject: Re: [Intel-gfx] [PATCH 00/22] Fallback to native backlight
Date: Mon, 24 Oct 2022 15:23:46 +0200 [thread overview]
Message-ID: <84d86b61-7694-2e22-3593-b11b3ce33cf8@redhat.com> (raw)
In-Reply-To: <20221024131451.lvkesdg3kvyvbi7n@pali>
Hi,
On 10/24/22 15:14, Pali Rohár wrote:
> On Monday 24 October 2022 21:58:57 Akihiko Odaki wrote:
>> Regarding the second limitation, I don't even understand the difference
>> between vendor and native. My guess is that a vendor backlight device uses
>> vendor-specific ACPI interface, and a native one directly uses hardware
>> registers. If my guess is correct, the difference between vendor and native
>> does not imply that both of them are likely to exist at the same time. As
>> the conclusion, there is no more motivation to try to de-duplicate the
>> vendor/native combination than to try to de-duplicate combination of devices
>> with a single type.
>
> Hello! I just want to point one thing. On some Dell laptops there are
> 3 different ways (= 3 different APIs) how to control display backlight.
> There is ACPI driver (uses ACPI), GPU/DRM driver (i915.ko; uses directly
> HW) and platform vendor driver (dell-laptop.ko; uses vendor BIOS or
> firmware API).
Right and that is just one example of laptops which can register both
vendor + native backlight devices, which is why this whole series is
a bad idea.
Regards,
Hans
> Just every driver has different pre-calculated scaling
> values. So sometimes user wants to choose different driver just because
> it allows to set backlight level with "better" granularity. Registering
> all 3 device drivers is bad as user does not want to see 3 display
> panels and forcing registration of specific one without runtime option
> is also bad (some of those drivers do not have to be suitable or has
> worse granularity as other).
WARNING: multiple messages have this Message-ID (diff)
From: Hans de Goede <hdegoede@redhat.com>
To: "Pali Rohár" <pali@kernel.org>,
"Akihiko Odaki" <akihiko.odaki@daynix.com>
Cc: 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>,
Jonathan Corbet <corbet@lwn.net>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Len Brown <lenb@kernel.org>,
Jani Nikula <jani.nikula@linux.intel.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
"Lee, Chun-Yi" <jlee@suse.com>, Mark Gross <markgross@kernel.org>,
Corentin Chary <corentin.chary@gmail.com>,
Cezary Jackiewicz <cezary.jackiewicz@gmail.com>,
Matthew Garrett <mjg59@srcf.ucam.org>,
Jonathan Woithe <jwoithe@just42.net>,
Ike Panhc <ike.pan@canonical.com>,
Daniel Dadap <ddadap@nvidia.com>,
Kenneth Chan <kenneth.t.chan@gmail.com>,
Mattia Dongili <malattia@linux.it>,
Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
Azael Avalos <coproscefalo@gmail.com>, Lee Jones <lee@kernel.org>,
Daniel Thompson <daniel.thompson@linaro.org>,
Jingoo Han <jingoohan1@gmail.com>, Helge Deller <deller@gmx.de>,
Robert Moore <robert.moore@intel.com>,
dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
intel-gfx@lists.freedesktop.org,
platform-driver-x86@vger.kernel.org,
acpi4asus-user@lists.sourceforge.net,
ibm-acpi-devel@lists.sourceforge.net,
linux-fbdev@vger.kernel.org, devel@acpica.org
Subject: Re: [PATCH 00/22] Fallback to native backlight
Date: Mon, 24 Oct 2022 15:23:46 +0200 [thread overview]
Message-ID: <84d86b61-7694-2e22-3593-b11b3ce33cf8@redhat.com> (raw)
In-Reply-To: <20221024131451.lvkesdg3kvyvbi7n@pali>
Hi,
On 10/24/22 15:14, Pali Rohár wrote:
> On Monday 24 October 2022 21:58:57 Akihiko Odaki wrote:
>> Regarding the second limitation, I don't even understand the difference
>> between vendor and native. My guess is that a vendor backlight device uses
>> vendor-specific ACPI interface, and a native one directly uses hardware
>> registers. If my guess is correct, the difference between vendor and native
>> does not imply that both of them are likely to exist at the same time. As
>> the conclusion, there is no more motivation to try to de-duplicate the
>> vendor/native combination than to try to de-duplicate combination of devices
>> with a single type.
>
> Hello! I just want to point one thing. On some Dell laptops there are
> 3 different ways (= 3 different APIs) how to control display backlight.
> There is ACPI driver (uses ACPI), GPU/DRM driver (i915.ko; uses directly
> HW) and platform vendor driver (dell-laptop.ko; uses vendor BIOS or
> firmware API).
Right and that is just one example of laptops which can register both
vendor + native backlight devices, which is why this whole series is
a bad idea.
Regards,
Hans
> Just every driver has different pre-calculated scaling
> values. So sometimes user wants to choose different driver just because
> it allows to set backlight level with "better" granularity. Registering
> all 3 device drivers is bad as user does not want to see 3 display
> panels and forcing registration of specific one without runtime option
> is also bad (some of those drivers do not have to be suitable or has
> worse granularity as other).
next prev parent reply other threads:[~2022-10-24 13:24 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-24 11:34 [PATCH 00/22] Fallback to native backlight Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 01/22] drm/i915/opregion: Improve backlight request condition Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 02/22] ACPI: video: Introduce acpi_video_get_backlight_types() Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 03/22] LoongArch: Use acpi_video_get_backlight_types() Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 04/22] platform/x86: acer-wmi: " Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 05/22] platform/x86: asus-laptop: " Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 06/22] platform/x86: asus-wmi: " Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 07/22] platform/x86: compal-laptop: " Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:34 ` [PATCH 08/22] platform/x86: eeepc-laptop: " Akihiko Odaki
2022-10-24 11:34 ` Akihiko Odaki
2022-10-24 11:34 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 09/22] platform/x86: fujitsu-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 22:24 ` Jonathan Woithe
2022-10-24 22:24 ` [Intel-gfx] " Jonathan Woithe
2022-10-24 22:24 ` Jonathan Woithe
2022-10-24 11:35 ` [PATCH 10/22] platform/x86: ideapad-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 11/22] platform/x86: msi-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 12/22] platform/x86: msi-wmi: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 13/22] platform/x86: nvidia-wmi-ec-backlight: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 14/22] platform/x86: panasonic-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 15/22] platform/x86: samsung-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 16/22] platform/x86: sony-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 17/22] platform/x86: thinkpad_acpi: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 18/22] platform/x86: toshiba_acpi: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 19/22] platform/x86: dell-laptop: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 20/22] platform/x86: intel_oaktrail: " Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 21/22] ACPI: video: Remove acpi_video_get_backlight_type() Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:35 ` [PATCH 22/22] ACPI: video: Fallback to native backlight Akihiko Odaki
2022-10-24 11:35 ` Akihiko Odaki
2022-10-24 11:35 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 11:48 ` [PATCH 00/22] " Jani Nikula
2022-10-24 11:48 ` Jani Nikula
2022-10-24 11:48 ` [Intel-gfx] " Jani Nikula
2022-10-24 11:56 ` Akihiko Odaki
2022-10-24 11:56 ` Akihiko Odaki
2022-10-24 11:56 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 12:00 ` Hans de Goede
2022-10-24 12:00 ` Hans de Goede
2022-10-24 12:00 ` [Intel-gfx] " Hans de Goede
2022-10-24 11:53 ` Hans de Goede
2022-10-24 11:53 ` Hans de Goede
2022-10-24 11:53 ` [Intel-gfx] " Hans de Goede
2022-10-24 12:58 ` Akihiko Odaki
2022-10-24 12:58 ` Akihiko Odaki
2022-10-24 12:58 ` Akihiko Odaki
2022-10-24 13:14 ` Pali Rohár
2022-10-24 13:14 ` Pali Rohár
2022-10-24 13:14 ` [Intel-gfx] " Pali Rohár
2022-10-24 13:23 ` Hans de Goede [this message]
2022-10-24 13:23 ` Hans de Goede
2022-10-24 13:23 ` [Intel-gfx] " Hans de Goede
2022-10-24 13:21 ` Hans de Goede
2022-10-24 13:21 ` Hans de Goede
2022-10-24 13:21 ` [Intel-gfx] " Hans de Goede
2022-10-24 14:06 ` Akihiko Odaki
2022-10-24 14:06 ` Akihiko Odaki
2022-10-24 14:06 ` Akihiko Odaki
2022-10-24 14:31 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 14:31 ` Akihiko Odaki
2022-10-24 14:31 ` Akihiko Odaki
2022-10-24 14:37 ` Hans de Goede
2022-10-24 14:37 ` Hans de Goede
2022-10-24 14:37 ` [Intel-gfx] " Hans de Goede
2022-10-24 15:00 ` Akihiko Odaki
2022-10-24 15:00 ` Akihiko Odaki
2022-10-24 15:00 ` Akihiko Odaki
2022-10-24 18:11 ` Jani Nikula
2022-10-24 18:11 ` Jani Nikula
2022-10-24 18:11 ` [Intel-gfx] " Jani Nikula
2022-10-25 3:23 ` Akihiko Odaki
2022-10-25 3:23 ` Akihiko Odaki
2022-10-25 3:23 ` [Intel-gfx] " Akihiko Odaki
2022-10-24 16:39 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
2022-10-24 16:39 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork
2022-10-24 17:16 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork
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