From: Javier Martinez Canillas <javierm@redhat.com>
To: Thomas Zimmermann <tzimmermann@suse.de>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 31/37] drm: rcar-du: Add support for the nomodeset kernel parameter
Date: Fri, 28 Jan 2022 12:09:05 +0100 [thread overview]
Message-ID: <9ae2c7ba-133e-7c6f-190b-97158f241c7f@redhat.com> (raw)
In-Reply-To: <584f1343-b285-bf8e-e48c-764c2a56bce3@suse.de>
On 1/28/22 11:46, Thomas Zimmermann wrote:
> Am 28.01.22 um 11:34 schrieb Laurent Pinchart:
[snip]
>>>
>>> It cannot be 'mode-setted'. We get a pre-configured framebuffer from the
>>> firmware or bootloader. Whatever we draw there shows up on the screen.
>>
>> I doubt that's going to work as you expect, clocks and regulators will
>> get disabled at boot if not used by any driver.
>
> Simpledrm and simplefb attach to these firmware framebuffers. Both
> drivers look at the device tree nodes to acquire the relevant clocks and
> regulators.
>
Laurent is correct that in some cases it might be an issue. For example, if
a SystemReady ES image is booted using the U-boot EFI stub instead of bootz.
In this case the system will be presented as EFI and the firmware framebuffer
just taken from the EFI GOP. There won't be any Device Tree node describing
the clocks, regulators, etc that are required for the framebuffer to work.
The user then will have to pass clk_ignore_unused, pd_ignore_unused and maybe
other cmdline params (or even hack a DT to set regulator-always-on for needed
regulators).
But that is also true if the user wants to disable the real DRM driver with
modprobe.blacklist=rcar-du-drm.
What this patch does is just to make all DRM drivers consistent and honour the
nomodeset param (whose name is really misleading but we can't change that).
Best regards,
--
Javier Martinez Canillas
Linux Engineering
Red Hat
WARNING: multiple messages have this Message-ID (diff)
From: Javier Martinez Canillas <javierm@redhat.com>
To: Thomas Zimmermann <tzimmermann@suse.de>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v2 31/37] drm: rcar-du: Add support for the nomodeset kernel parameter
Date: Fri, 28 Jan 2022 12:09:05 +0100 [thread overview]
Message-ID: <9ae2c7ba-133e-7c6f-190b-97158f241c7f@redhat.com> (raw)
In-Reply-To: <584f1343-b285-bf8e-e48c-764c2a56bce3@suse.de>
On 1/28/22 11:46, Thomas Zimmermann wrote:
> Am 28.01.22 um 11:34 schrieb Laurent Pinchart:
[snip]
>>>
>>> It cannot be 'mode-setted'. We get a pre-configured framebuffer from the
>>> firmware or bootloader. Whatever we draw there shows up on the screen.
>>
>> I doubt that's going to work as you expect, clocks and regulators will
>> get disabled at boot if not used by any driver.
>
> Simpledrm and simplefb attach to these firmware framebuffers. Both
> drivers look at the device tree nodes to acquire the relevant clocks and
> regulators.
>
Laurent is correct that in some cases it might be an issue. For example, if
a SystemReady ES image is booted using the U-boot EFI stub instead of bootz.
In this case the system will be presented as EFI and the firmware framebuffer
just taken from the EFI GOP. There won't be any Device Tree node describing
the clocks, regulators, etc that are required for the framebuffer to work.
The user then will have to pass clk_ignore_unused, pd_ignore_unused and maybe
other cmdline params (or even hack a DT to set regulator-always-on for needed
regulators).
But that is also true if the user wants to disable the real DRM driver with
modprobe.blacklist=rcar-du-drm.
What this patch does is just to make all DRM drivers consistent and honour the
nomodeset param (whose name is really misleading but we can't change that).
Best regards,
--
Javier Martinez Canillas
Linux Engineering
Red Hat
next prev parent reply other threads:[~2022-01-28 11:09 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-17 0:37 [PATCH v2 00/37] drm: Make drivers to honour the nomodeset parameter Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 01/37] drm: Add drm_module_{pci,platform}_driver() helper macros Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 01/37] drm: Add drm_module_{pci, platform}_driver() " Javier Martinez Canillas
2021-12-17 14:31 ` [PATCH v2 01/37] drm: Add drm_module_{pci,platform}_driver() " Thomas Zimmermann
2021-12-17 0:37 ` [PATCH v2 02/37] drm/hisilicon/hibmc: Use drm_module_pci_driver() to register the driver Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 03/37] drm/komeda: Use drm_module_platform_driver() " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 04/37] drm/arm/hdlcd: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 05/37] drm/malidp: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 06/37] drm/aspeed: " Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 07/37] drm/atmel-hlcdc: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 08/37] drm/fsl-dcu: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 09/37] drm/hisilicon/kirin: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 10/37] drm/imx/dcss: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 15:58 ` kernel test robot
2021-12-17 15:58 ` kernel test robot
2021-12-17 15:58 ` kernel test robot
2021-12-17 0:37 ` [PATCH v2 11/37] drm/kmb: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 12/37] drm/meson: " Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 13/37] drm: mxsfb: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 14/37] drm/shmobile: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 15/37] drm/stm: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 16/37] drm/sun4i: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 17/37] drm/tidss: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 18/37] drm/arc: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 19/37] drm/tve200: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 20/37] drm/xlnx: " Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 21/37] drm/armada: Add support for the nomodeset kernel parameter Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 22/37] drm/exynos: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 23/37] drm/gma500: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 24/37] drm/hyperv: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-20 17:10 ` Deepak Rawat
2021-12-17 0:37 ` [PATCH v2 25/37] drm/imx: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 26/37] drm/ingenic: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 27/37] drm/mcde: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 28/37] drm/mediatek: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 29/37] drm/msm: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 30/37] drm/omap: " Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 31/37] drm: rcar-du: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2022-01-28 9:13 ` Kieran Bingham
2022-01-28 9:33 ` Thomas Zimmermann
2022-01-28 10:34 ` Laurent Pinchart
2022-01-28 10:46 ` Thomas Zimmermann
2022-01-28 11:04 ` Laurent Pinchart
2022-01-28 11:26 ` Thomas Zimmermann
2022-01-28 11:36 ` Laurent Pinchart
2022-01-28 11:53 ` Thomas Zimmermann
2022-01-28 11:09 ` Javier Martinez Canillas [this message]
2022-01-28 11:09 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 32/37] drm/rockchip: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 33/37] drm/sprd: " Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 34/37] drm/sti: " Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 35/37] drm/tegra: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 0:37 ` [PATCH v2 36/37] drm/tilcdc: " Javier Martinez Canillas
2021-12-17 0:37 ` Javier Martinez Canillas
2021-12-17 13:30 ` Jyri Sarha
2021-12-17 13:30 ` Jyri Sarha
2021-12-17 0:37 ` [PATCH v2 37/37] drm/xen: " Javier Martinez Canillas
2022-01-27 18:29 ` [PATCH v2 00/37] drm: Make drivers to honour the nomodeset parameter Javier Martinez Canillas
2022-01-27 18:29 ` Javier Martinez Canillas
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