Re: [PATCH 2/2] drm/tiny: Add ofdrm for Open Firmware framebuffers

From: Thomas Zimmermann <tzimmermann@suse.de>
To: "Geert Uytterhoeven" <geert@linux-m68k.org>,
	"Michal Suchánek" <msuchanek@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Helge Deller <deller@gmx.de>, Maxime Ripard <maxime@cerno.tech>,
	Sam Ravnborg <sam@ravnborg.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	DRI Development <dri-devel@lists.freedesktop.org>,
	Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 2/2] drm/tiny: Add ofdrm for Open Firmware framebuffers
Date: Thu, 19 May 2022 09:27:53 +0200	[thread overview]
Message-ID: <29a8201d-3c0c-eeed-81af-92b351880702@suse.de> (raw)
In-Reply-To: <CAMuHMdUws2eJ4pHng4GD0PjuvMj5Hef_y_YyM4fUJV9xdUVuEQ@mail.gmail.com>

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Hi

Am 19.05.22 um 09:11 schrieb Geert Uytterhoeven:
> Hi Michal,
> 
> On Wed, May 18, 2022 at 8:54 PM Michal Suchánek <msuchanek@suse.de> wrote:
>> On Wed, May 18, 2022 at 08:30:06PM +0200, Thomas Zimmermann wrote:
>>> --- a/drivers/gpu/drm/tiny/Kconfig
>>> +++ b/drivers/gpu/drm/tiny/Kconfig
>>> @@ -51,6 +51,18 @@ config DRM_GM12U320
>>>         This is a KMS driver for projectors which use the GM12U320 chipset
>>>         for video transfer over USB2/3, such as the Acer C120 mini projector.
>>>
>>> +config DRM_OFDRM
>>> +     tristate "Open Firmware display driver"
>>> +     depends on DRM && MMU && PPC
>>
>> Does this build with !PCI?
>>
>> The driver uses some PCI functions, so it might possibly break with
>> randconfig. I don't think there are practical !PCI PPC configurations.
> 
> IIRC, the first PowerMacs didn't have PCI.

I'll try to build without PCI to see what happens.

Those old Macs use BootX, right? BootX is not supported ATM, as I don't 
have the HW to test. Is there an emulator for it?

If anyone what's to make patches for BootX, I'd be happy to add them. 
The offb driver also supports a number of special cases for palette 
handling. That might be necessary for ofdrm as well.

Best regards
Thomas

> 
> Gr{oetje,eeting}s,
> 
>                          Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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