Using acceleration method UXA instead of SNA worked

Blurred? A screenshot would be very descriptive. And please attach your Xorg.0.log.

If you can manage a bisect, since you have two close versions you should be able to track down the mystery commit in a few minutes.

Created attachment 116710 [details]
Screenshot

Screenshot shows blurring

Created attachment 116711 [details]
Xorg.0.log

Hmm, that is not using the -intel driver. Mind double checking the setup corresponds with the error?

[  1047.491] (EE) Failed to load module "intel" (module does not exist, 0)

Building from -intel.git would also be a useful verification step.

Created attachment 116712 [details]
Xorg log

I'm experiencing a similar issue.
My terminal emulator has very poor performance and some programs don't show text.
General system performance is way worse.

Using version: 1:2.99.917+364+gb24e758-1, Thinkpad X1 Carbon, Intel Core i7 3667U with an Intel HD Graphics 4000 
Downgrading to 2.99.917-5 helped as well.

(In reply to mohlerm from comment #6)
> Created attachment 116712 [details]
> Xorg log
> 
> I'm experiencing a similar issue.
> My terminal emulator has very poor performance and some programs don't show
> text.
> General system performance is way worse.
> 
> Using version: 1:2.99.917+364+gb24e758-1, Thinkpad X1 Carbon, Intel Core i7
> 3667U with an Intel HD Graphics 4000 
> Downgrading to 2.99.917-5 helped as well.

Please file a separate report since it is not very similar at all.

Created attachment 116759 [details]
example screenshot

I'm seeing the same thing. GM45, xf86-video-intel latest git, SNA.

Switching to UXA solves the problem. Don't know if this is related, but I recently had to go back to 3GB (2+1) of RAM.

Created attachment 116760 [details]
xorg log

(In reply to Edward Sheldrake from comment #8)
> Created attachment 116759 [details]
> example screenshot
> 
> I'm seeing the same thing. GM45, xf86-video-intel latest git, SNA.
> 
> Switching to UXA solves the problem. Don't know if this is related, but I
> recently had to go back to 3GB (2+1) of RAM.

For you 3GiB system, I think you need this kernel patch:

diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index d16585f788ea..ff96ae9b77bc 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -447,7 +447,10 @@ i915_gem_get_tiling(struct drm_device *dev, void *data,
        }
 
        /* Hide bit 17 from the user -- see comment in i915_gem_set_tiling */
-       args->phys_swizzle_mode = args->swizzle_mode;
+       if (dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES)
+               args->phys_swizzle_mode = I915_BIT_6_SWIZZLE_UNKNOWN;
+       else
+               args->phys_swizzle_mode = args->swizzle_mode;
        if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_17)
                args->swizzle_mode = I915_BIT_6_SWIZZLE_9;
        if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17)

That kernel patch has completely fixed the problem for me.

The kernel patch has not hit Linus' tree, yet. Is it queued anywhere?

The original patch has been reviewed, just stalling on Jani at the moment as I made a suggestion about doing it in an alternate fashion and that alternate patch is sitting around distracting people.

And hopefully we won't have to revert this one....

commit 5eb3e5a5e11d14f9deb2a4b83555443b69ab9940
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Jun 28 09:19:26 2015 +0100

    drm/i915: Declare the swizzling unknown for L-shaped configurations

*** Bug 94110 has been marked as a duplicate of this bug. ***