Re: [PATCH v2 2/5] fbdev: Give atafb proper parent

[Michael Schmitz <schmitzmic@gmail.com>]

Hi Thomas,

Am 17.08.2026 um 19:57 schrieb Thomas Zimmermann:
>>>> The atafb fb device registers no parent, causing a missing symlink
>>>> (/sys/class/graphics/fb0/device). Xorg fbdevhw driver looks for that
>>>> symlink when scanning for devices, so add a parent node for atafb.
>>>
>>> Do you really have these devices to test with?
>>
>> Not the particular hardware that patches 3 and 4 add support for, but
>> the 'normal' Videl that is found in every Falcon, yes.

N.B.: actual hardware won't be essential to test - an emulator such as 
ARAnyM will do fine.

>>
>>> If so, could you also replace the hard coded fb_info with a call to
>>> framebuffer_alloc()?
>>
>> Can't see how that would work - fb_info isn't passed to all functions
>> that need to use it, especially in the hardware detection phase (hence
>> the use of a static fb_info struct)?

On second thought, depending on how early in driver init fb_info is 
needed, I may get away with turning it into a struct *fb_info and using 
that where it can't easily be passed.

>
> You'd have to modify the driver to pass the allocated instance, of
> course. It's not a trivial oneliner, but if this driver is still
> relevant, it might be worth improving it.

Your point is taken - I'll take a look at what would be required to pass 
fb_info to all users. It's been nineteen years since rewrote atafb so 
getting my head around the call sequences may take awhile.

Cheers,

	Michael

>
> Best regards
> Thomas
>
>>
>> Cheers,
>>
>>     Michael
>>
>>>>
>>>> Signed-off-by: Miro Kropacek <miro.kropacek@gmail.com>
>>>> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
>>>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>>>> Cc: <linux-fbdev@vger.kernel.org>
>>>> Link: https://lists.debian.org/debian-68k/2026/08/msg00000.html
>>>> ---
>>>>   drivers/video/fbdev/atafb.c | 5 +++++
>>>>   1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
>>>> index b8ed1c537293..3d540803dc2b 100644
>>>> --- a/drivers/video/fbdev/atafb.c
>>>> +++ b/drivers/video/fbdev/atafb.c
>>>> @@ -3101,6 +3101,11 @@ static int __init atafb_probe(struct
>>>> platform_device *pdev)
>>>>   #endif /* ATAFB_EXT */
>>>>     //    strcpy(fb_info.mode->name, "Atari Builtin ");
>>>> +    /* Parent the fb device properly: without this fb0 registers as a
>>>> +     * virtual sysfs device with no /sys/class/graphics/fb0/device
>>>> link,
>>>> +     * which makes Xorg's fbdevhw reject it ("No devices detected").
>>>> +     */
>>>> +    fb_info.device = &pdev->dev;
>>>
>>> Because this is supposed to happen in framebuffer_alloc() and keeping it
>>> there would be preferable.
>>>
>>> Best regards
>>> Thomas
>>>
>>>>       fb_info.fbops = &atafb_ops;
>>>>       // try to set default (detected; requested) var
>>>>       do_fb_set_var(&atafb_predefined[default_par - 1], 1);
>>>
>>
>