[SOLVED] Re: Radeon HD 4250: screen going blank every few seconds

[Andrea Venturoli]

On 12/31/18 3:04 PM, Andrea Venturoli wrote:
> On 12/31/18 8:27 AM, Andrea Venturoli wrote:
> 
>>> The graphics hardware you're using is also quite old, and not very 
>>> well supported.
>>
>> I've been using an HD4200 for several years: it's listed as "Works" on 
>> the AMD-GPU-Matrix page and I've been very happy with it.
>>
>> AFAICT, HD4250 should be the same chip (RS880), just with a slightly 
>> higher clock and some dedicated RAM, so I thought it would work as 
>> well (and with the same configuration).
>> I understand the devil is in the details, though.
> 
> I think I reached a *good* configuration by trial and error.
> 
> I went into BIOS settings and disabled HDMI audio (probably not 
> something that matters) and choose to use only "sideport" memory (not 
> "UMA" or "sideport+UMA").
> 
> At this point, with a DVI cable I can achieve full resolution 
> (1920x1200) without glitches.
> 
> As I'm happy with this, I'm not trying which of the two settings was the 
> culprit, whether this works with an HDMI cable too, changing X.Org 
> version or driver/kernel module, etc... :)

Again I was too hasty, the trouble has not gone away completely: while 
it happened every 2-3 seconds before, now it can go hours without doing 
it, but suddenly it can come up again.
This would not be too much of a trouble (although it's annoying), but 
enabling/disabling a second monitor or changing resolution or 
who-knows-what can get me back in the 2-3 seconds loop.

So I removed all kmods ports and switched to xf86-video-ati-legacy: so 
far so good, but then again it also seemed good before...
Time will tell if this is it.

In case, I'll try tijl's patch, moving to standard X.Org version, etc...

  bye & Thanks
	av.