Users of x11-drivers/xf86-video-ati-legacy

[Niclas Zeising]

On 2020-04-13 11:42, Andrea Venturoli wrote:
> On 2020-04-13 09:29, Niclas Zeising wrote:
> 
>> Thank you for helping out and testing, unfortunately there is not much 
>> to do if it does not work.
> 
> Thanks to you.
> 
> 
> 
>> I don't have the time or hardware to get an older xf86-video-ati to 
>> maybe build with xserver 1.20.
> 
> I'm now back to xserver 1.19.
> I can easily switch back and forth, so if you want me to do some test, 
> just ask.
> In fact, I'd be interested in making this work, but I need some 
> guidance; I can use gdb & Co, but I know almost nothing of X internals.

I don't know exactly what makes xf86-video-ati-legacy crash, but if you 
want to get it working, I think that the best course of action is to 
move it back to 7.9, and then try to backport just as much as needed to 
get it to compile with xserver 1.20, but still work on drm-legacy-kmod. 
That's what I tried to do, but unfortunately I probably brought back too 
much, which caused it to break.
> 
> 
> 
>> The reason xf86-video-ati-legacy works with drm-fbsd12.0-kmod is that 
>> the updated kmod uses newer APIs etc.
> 
> You mean the reason *it doesn't* work?

Yes, of course.  Sorry about that.
> 
> 
> 
>>   At one point, xf86-video-ati was updated to make these work, and 
>> when we updated xf86-video-ati in ports to the latest version to get 
>> support for more modern hardware,we had to create 
>> xf86-video-ati-legacy for use with drm-legacy-kmod.  This was always 
>> one of those stop-gap measures.
> 
> Ok.
> Problem is xf86-video-ati-legacy + drm-kmod-legacy works no more with 
> Xorg 1.20.
> And, more relevantly, on my HD4250 drm-12-kmod only works partially.
> And, even with those limiations, X often hangs.
> 
> Strange, because I also have a HD4200 which used to work prefectly with 
> non-legacy; I had to switch to legacy when I moved to HD4250.
> They should be almost the same card, just with different clocks.

Graphics cards, even in the same series, can be quite different, 
unfortunately.  This is one of the reasons this work is so hard, because 
even if one adapter in a family works, it does not mean all of them does.
Looking quickly at wikipedia [1], it looks like the HD4200 card uses the 
785G chipset, but HD4250 uses 880G (a generation later, as I understand 
it), meaning they are probably quite different.  Yes, this is super 
confusing.

[1] https://en.wikipedia.org/wiki/Radeon_HD_4000_series#IGP_(HD_4000)

Regards
-- 
Niclas Zeising