Intel UMS Support To Be Eliminated In Linux 3.16 Kernel

[danvet]

I didn't mean to say that the support is being killed.... Just that it's with old i8xx/i9xx hardware where KMS problems occur most frequently. With the latest KMS code, is everything jolly for that hardware? Last I heard there were still some issues with i845~i915.

We have some lingering issues on some funky gen2/3 machines (and if people with too much time asked I can give pointers to what needs to be done), but afaik there are no regressions left for upgrading from UMS to KMS. So the only recourse for people troubled with gen2/3 bugs is to not to use UMS but to fall back on VBIOS modesetting using vesa and sw rendering for everything. Which is exactly what the transparent fallback will be once UMS support in the kernel i915.ko driver is gone.

For those curious: Iirc the last UMS->KMS regression we've had was a performance issue on old legacy X apps because UMS supported XAA and UXA didn't accelerated those old X blitter operations at all. But Chris' SNA fixed this over a year ago. Otherwise I'm not aware of any UMS->KMS regression in recent years (there have been a few even longer ago, but should all be addressed meanwhile).

[Rexilion]

I didn't mean to say that the support is being killed.... Just that it's with old i8xx/i9xx hardware where KMS problems occur most frequently. With the latest KMS code, is everything jolly for that hardware? Last I heard there were still some issues with i845~i915.

This sentence frightens me:

If you are trying to run Linux on an old Intel i8xx/9xx chipset, you're best off using a few-year-old Linux distribution as the user-space mode-setting code-paths have been completely unmaintained for some time and Intel developers really aren't concerned about this ancient hardware...

But I guess these *are* supported by KMS.

You will only run into trouble if you are using UMS right now.

[Michael]

Just a quick clarification: For old i8xx/i9xx chips we _don't_ kill the support, kernel modesetting will still work fine and has for the past 5 years or so. The only thing we'll kill is support for userspace mode setting, which stopped being support by the userspace X drivers about 5 years ago. If you have upgraded your distro in that time-frame there's absolutely no change at all for you. And even if you still use the old drivers the fallback to software rendering should be fairly seamless.

After all this is an open-source driver and not a blob where users regularly get left in the cold!

I didn't mean to say that the support is being killed.... Just that it's with old i8xx/i9xx hardware where KMS problems occur most frequently. With the latest KMS code, is everything jolly for that hardware? Last I heard there were still some issues with i845~i915.

[danvet]

Old hw support will _not_ be killed

Just a quick clarification: For old i8xx/i9xx chips we _don't_ kill the support, kernel modesetting will still work fine and has for the past 5 years or so. The only thing we'll kill is support for userspace mode setting, which stopped being support by the userspace X drivers about 5 years ago. If you have upgraded your distro in that time-frame there's absolutely no change at all for you. And even if you still use the old drivers the fallback to software rendering should be fairly seamless.

After all this is an open-source driver and not a blob where users regularly get left in the cold!

[phoronix]

Phoronix: Intel UMS Support To Be Eliminated In Linux 3.16 Kernel

For those Intel owners -- namely those with vintage Intel hardware -- the days of using user-space mode-setting (UMS) for the open-source Linux graphics driver are running out...

http://www.phoronix.com/vr.php?view=MTY0OTA