# Intel - pipe is still busy with an old pageflip

## siebz0r

Recently my system 'freezes' when I'm gaming. Usually about half an hour after I started a game, the graphics freeze. The rest of the system becomes (nearly) unusable. Sometimes the audio just loops until I power off the system forcefully and sometimes the game seems to continue (based on the audio).

Killing the game or X doesn't seem to help. The only way to make the system usable again is to reboot.

On one occasion I managed to switch to a TTY, this allowed me to view dmesg. The error that seems to cause this looks like this:

```
*ERROR* pipe is still busy with an old pageflip 
```

Searching the internet for solutions, I came across this Reddit thread. It seems to describe the same problem.

Someone mentions this issue appears since 3.16:

 *Quote:*   

> An Intel driver maintainer told me it's an issue introduced since kernel 3.16. And there's no fix for it because they still haven't found out what's causing the problem.
> 
> 

 

I have downgraded to 3.15, but I still get this issue.

I have also read somewhere else that this issue should be fixed in 3.19, but this kernel isn't released yet.

I'm willing to downgrade kernels to work around this problem, but I don't know how far I need to go. Does anyone have more information or a possible workaround?

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## eccerr0r

I'm currently trying to install Gentoo on a tablet, and run into this on an Intel HD4000 graphics subsystem (Z3735G SoC) except this happens during (cold) boot when trying to switch video modes.  I've been using 3.19-rc3 but see this behavior as well, and I can't say if I see the slowdown as I'm having timer problems with this platform.  You could also try different version of Mesa and see if that changes behavior?

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## Ant P.

I updated my netbook from kernel 3.17.3 to 3.18.1 and started getting huge graphical corruption (of the "diagonal triangles splitting the screen in two" variety), finding the following in dmesg. It mentions pageflips too, so I'm wondering: same root cause maybe?

```
[13142.669720] ------------[ cut here ]------------

[13142.669744] WARNING: CPU: 0 PID: 435 at drivers/gpu/drm/i915/intel_display.c:9916 intel_check_page_flip+0xa7/0xb0()

[13142.669750] Kicking stuck page flip: queued at 121943, now 121944

[13142.669754] Modules linked in: [last unloaded: microcode]

[13142.669767] CPU: 0 PID: 435 Comm: X Tainted: G     U  W 3.18.1-zen+local-170389-gfd99d59307f2 #1

[13142.669772] Hardware name: ASUSTeK Computer INC. 1000H/1000H, BIOS 2204 10/21/2009

[13142.669778]  000026bc c162d016 f528be7c c103c5fa c177bd68 f528be94 000001b3 c17799c0

[13142.669792]  000026bc c1387487 c1387487 f68dd000 f6996cfc 00000001 f6996c00 c103c644

[13142.669805]  00000009 f528be7c c177bd68 f528be94 c1387487 c17799c0 000026bc c177bd68

[13142.669818] Call Trace:

[13142.669833]  [<c162d016>] ? dump_stack+0x45/0x65

[13142.669845]  [<c103c5fa>] ? warn_slowpath_common+0x7a/0x90

[13142.669854]  [<c1387487>] ? intel_check_page_flip+0xa7/0xb0

[13142.669862]  [<c1387487>] ? intel_check_page_flip+0xa7/0xb0

[13142.669871]  [<c103c644>] ? warn_slowpath_fmt+0x34/0x40

[13142.669879]  [<c1387487>] ? intel_check_page_flip+0xa7/0xb0

[13142.669890]  [<c135e1be>] ? i915_handle_vblank+0x3e/0x80

[13142.669898]  [<c13627f4>] ? i915_irq_handler+0x264/0x300

[13142.669909]  [<c1062a87>] ? handle_irq_event_percpu+0x27/0x100

[13142.669918]  [<c1062b89>] ? handle_irq_event+0x29/0x40

[13142.669926]  [<c1064e46>] ? handle_fasteoi_irq+0x66/0x110

[13142.669935]  [<c10041d0>] ? handle_irq+0x30/0x80

[13142.669943]  [<c1003b62>] ? do_IRQ+0x32/0xc0

[13142.669952]  [<c106e020>] ? hrtimer_init+0x10/0x10

[13142.669960]  [<c1070a11>] ? SyS_clock_gettime+0x51/0x80

[13142.669970]  [<c163406c>] ? common_interrupt+0x2c/0x34

[13142.669976] ---[ end trace 4e34db6035dd357a ]---
```

No crashes from it, but I didn't stick around long enough to see if it would.

Note: I did do a whole bunch of other updates along with the kernel, about 2-3 weeks worth, but just going back to 3.17 seemed to be enough to restore sanity.

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