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

[Thomas Zimmermann <tzimmermann@suse.de>]

Am 17.08.26 um 09:49 schrieb Michael Schmitz:
> Hi Thomas,
>
> Am 17.08.2026 um 18:34 schrieb Thomas Zimmermann:
>> Hi
>>
>> Am 16.08.26 um 09:37 schrieb Michael Schmitz:
>>> From: Miro Kropacek <miro.kropacek@gmail.com>
>>>
>>> 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.
>
>> 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)?

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.

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);
>>
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)