[ 3.14.0-12041-g75ff24f ] regression: drm warning

[Jörg Otte]

Kernel 3.14.0-12041-g75ff24f from 9.4.2014 introduces the following
on the console (driver is i915):

[drm:ivb_err_int_handler] *ERROR* Pipe B FIFO underrun
[drm:cpt_serr_int_handler] *ERROR* PCH transcoder A FIFO underrun
[drm:cpt_serr_int_handler] *ERROR* PCH transcoder B FIFO underrun

In syslog I find:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1 at
/data/kernel/linux/drivers/gpu/drm/drm_mm.c:211 0xffffffffb22a70fa()
no hole found for node 0x0 + 0x300000
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.14.0-12041-g75ff24f #45
Hardware name: FUJITSU LIFEBOOK AH532/FJNBB1C, BIOS Version 1.09 05/22/2012
 0000000000000000 ffffffffb2967138 ffffffffb262ae5d ffff8802160d5a58
 ffffffffb20391ad ffff880214994000 0000000000300000 0000000000000000
 ffff880214952800 0000000000000000 ffffffffb2039255 ffffffffb2967190
Call Trace:
 [<ffffffffb262ae5d>] ? 0xffffffffb262ae5d
 [<ffffffffb20391ad>] ? 0xffffffffb20391ad
 [<ffffffffb2039255>] ? 0xffffffffb2039255
 [<ffffffffb22a70fa>] ? 0xffffffffb22a70fa
 [<ffffffffb22d4b11>] ? 0xffffffffb22d4b11
 [<ffffffffb2300f92>] ? 0xffffffffb2300f92
 [<ffffffffb232af7b>] ? 0xffffffffb232af7b
 [<ffffffffb232f675>] ? 0xffffffffb232f675
 [<ffffffffb21fa38c>] ? 0xffffffffb21fa38c
 [<ffffffffb232ec04>] ? 0xffffffffb232ec04
 [<ffffffffb2622997>] ? 0xffffffffb2622997
 [<ffffffffb232ee62>] ? 0xffffffffb232ee62
 [<ffffffffb22a6a5b>] ? 0xffffffffb22a6a5b
 [<ffffffffb22a3994>] ? 0xffffffffb22a3994
 [<ffffffffb22a5a38>] ? 0xffffffffb22a5a38
 [<ffffffffb221a019>] ? 0xffffffffb221a019
 [<ffffffffb23327b8>] ? 0xffffffffb23327b8
 [<ffffffffb2332a03>] ? 0xffffffffb2332a03
 [<ffffffffb2332970>] ? 0xffffffffb2332970
 [<ffffffffb2330c45>] ? 0xffffffffb2330c45
 [<ffffffffb2331534>] ? 0xffffffffb2331534
 [<ffffffffb2332fce>] ? 0xffffffffb2332fce
 [<ffffffffb2aa2cc5>] ? 0xffffffffb2aa2cc5
 [<ffffffffb2a7fe45>] ? 0xffffffffb2a7fe45
 [<ffffffffb2052100>] ? 0xffffffffb2052100
 [<ffffffffb2a7ffe2>] ? 0xffffffffb2a7ffe2
 [<ffffffffb2a7f79e>] ? 0xffffffffb2a7f79e
 [<ffffffffb2624d20>] ? 0xffffffffb2624d20
 [<ffffffffb2624d29>] ? 0xffffffffb2624d29
 [<ffffffffb263223c>] ? 0xffffffffb263223c
 [<ffffffffb2624d20>] ? 0xffffffffb2624d20
---[ end trace 0d3f14b61bc31dab ]---

This does not happen in 3.14.0-11030-ga7963eb from 8.4.2014 and never
before.

Suppose merge
12024   e9f37d3 Merge branch 'drm-next' of
git://people.freedesktop.org/~airlied/linux
produces this problem.

Jörg