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Chris Wilson 96dabe99ca drm/i915: Avoid busy-spinning on VLV_GLTC_PW_STATUS mmio
The busy-spin, as the first stage of intel_wait_for_register(), is
currently under suspicion for causing:

[   62.034926] NMI watchdog: Watchdog detected hard LOCKUP on cpu 1
[   62.034928] Modules linked in: i2c_dev i915 intel_gtt drm_kms_helper prime_numbers
[   62.034932] CPU: 1 PID: 183 Comm: kworker/1:2 Not tainted 4.11.0-rc7+ #471
[   62.034933] Hardware name:                  /        , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015
[   62.034934] Workqueue: pm pm_runtime_work
[   62.034936] task: ffff880275a04ec0 task.stack: ffffc900002d8000
[   62.034936] RIP: 0010:__intel_wait_for_register_fw+0x77/0x1a0 [i915]
[   62.034937] RSP: 0018:ffffc900002dbc38 EFLAGS: 00000082
[   62.034939] RAX: ffffc90003530094 RBX: 0000000000130094 RCX: 0000000000000001
[   62.034940] RDX: 00000000000000a1 RSI: ffff88027fd15e58 RDI: 0000000000000000
[   62.034941] RBP: ffffc900002dbc78 R08: 0000000000000002 R09: 0000000000000000
[   62.034942] R10: ffffc900002dbc18 R11: ffff880276429dd0 R12: ffff8802707c0000
[   62.034943] R13: 00000000000000a0 R14: 0000000000000000 R15: 00000000fffefc10
[   62.034945] FS:  0000000000000000(0000) GS:ffff88027fd00000(0000) knlGS:0000000000000000
[   62.034945] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   62.034947] CR2: 00007ffd3cd98ff8 CR3: 0000000274c19000 CR4: 00000000001006e0
[   62.034947] Call Trace:
[   62.034948]  intel_wait_for_register+0x77/0x140 [i915]
[   62.034949]  vlv_suspend_complete+0x23/0x5b0 [i915]
[   62.034950]  intel_runtime_suspend+0x16c/0x2a0 [i915]
[   62.034950]  pci_pm_runtime_suspend+0x50/0x180
[   62.034951]  ? pci_pm_runtime_resume+0xa0/0xa0
[   62.034952]  __rpm_callback+0xc5/0x210
[   62.034953]  rpm_callback+0x1f/0x80
[   62.034953]  ? pci_pm_runtime_resume+0xa0/0xa0
[   62.034954]  rpm_suspend+0x118/0x580
[   62.034955]  pm_runtime_work+0x64/0x90
[   62.034956]  process_one_work+0x1bb/0x3e0
[   62.034956]  worker_thread+0x46/0x4f0
[   62.034957]  ? __schedule+0x18b/0x610
[   62.034958]  kthread+0xff/0x140
[   62.034958]  ? process_one_work+0x3e0/0x3e0
[   62.034959]  ? kthread_create_on_node+

and related hard lockups in CI for byt and bsw.

Note this effectively reverts commits 41ce405e68 and b273669588
("drm/i915: Convert wait_for(I915_READ(reg)) to intel_wait_for_register()")

v2: Convert bool allow into a u32 mask for clarity and repeat the
comment on vlv rc6 timing to justify the 3ms timeout used for the wait (Ville)

Fixes: 41ce405e68 ("drm/i915: Convert wait_for(I915_READ(reg)) to intel_wait_for_register()")
Fixes: b273669588 ("drm/i915: Convert wait_for(I915_READ(reg)) to intel_wait_for_register()")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100718
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170421135815.11897-1-chris@chris-wilson.co.uk
Tested-by: Tomi Sarvela <tomi.p.sarvela@intel.com>
(cherry picked from commit 3dd14c04d7)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2017-04-26 16:28:42 +03:00
arch Linux 4.11-rc6 2017-04-11 07:40:42 +10:00
block blk-mq: Restart a single queue if tag sets are shared 2017-04-07 12:40:09 -06:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-03-31 12:11:32 -07:00
Documentation drm/panel: Changes for v4.12-rc1 2017-04-13 06:17:40 +10:00
drivers drm/i915: Avoid busy-spinning on VLV_GLTC_PW_STATUS mmio 2017-04-26 16:28:42 +03:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 2017-04-09 09:10:02 -07:00
include Merge branch 'msm-next' of git://people.freedesktop.org/~robclark/linux into drm-next 2017-04-11 07:47:02 +10:00
init mm: move mm_percpu_wq initialization earlier 2017-03-31 17:13:30 -07:00
ipc Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
kernel Linux 4.11-rc6 2017-04-11 07:40:42 +10:00
lib Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-04-02 09:18:59 -07:00
mm mm/mempolicy.c: fix error handling in set_mempolicy and mbind. 2017-04-08 10:57:55 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-05 20:17:38 -07:00
samples statx: Include a mask for stx_attributes in struct statx 2017-04-03 01:06:00 -04:00
scripts Linux 4.11-rc6 2017-04-11 07:40:42 +10:00
security Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
sound ALSA: hda - fix a problem for lineout on a Dell AIO machine 2017-03-31 10:58:26 +02:00
tools Linux 4.11-rc6 2017-04-11 07:40:42 +10:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt KVM/ARM Fixes for v4.11-rc6 2017-04-05 16:27:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: update Yakir Yang email address 2017-04-08 00:47:49 -07:00
COPYING
CREDITS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS Merge tag 'drm-misc-next-2017-04-07' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-04-11 07:41:10 +10:00
Makefile Linux 4.11-rc6 2017-04-09 09:49:44 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.