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Chris Wilson f8db4d051b drm/i915: Initialise breadcrumb lists on the virtual engine
With deferring the breadcrumb signalling to the virtual engine (thanks
preempt-to-busy) we need to make sure the lists and irq-worker are ready
to send a signal.

[41958.710544] BUG: kernel NULL pointer dereference, address: 0000000000000000
[41958.710553] #PF: supervisor write access in kernel mode
[41958.710556] #PF: error_code(0x0002) - not-present page
[41958.710558] PGD 0 P4D 0
[41958.710562] Oops: 0002 [#1] SMP
[41958.710565] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G     U            5.3.0+ #207
[41958.710568] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS BNKBL357.86A.0052.2017.0918.1346 09/18/2017
[41958.710602] RIP: 0010:i915_request_enable_breadcrumb+0xe1/0x130 [i915]
[41958.710605] Code: 8b 44 24 30 48 89 41 08 48 89 08 48 8b 85 98 01 00 00 48 8d 8d 90 01 00 00 48 89 95 98 01 00 00 49 89 4c 24 28 49 89 44 24 30 <48> 89 10 f0 80 4b 30 10 c6 85 88 01 00 00 00 e9 1a ff ff ff 48 83
[41958.710609] RSP: 0018:ffffc90000003de0 EFLAGS: 00010046
[41958.710612] RAX: 0000000000000000 RBX: ffff888735424480 RCX: ffff8887cddb2190
[41958.710614] RDX: ffff8887cddb3570 RSI: ffff888850362190 RDI: ffff8887cddb2188
[41958.710617] RBP: ffff8887cddb2000 R08: ffff8888503624a8 R09: 0000000000000100
[41958.710619] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8887cddb3548
[41958.710622] R13: 0000000000000000 R14: 0000000000000046 R15: ffff888850362070
[41958.710625] FS:  0000000000000000(0000) GS:ffff88885ea00000(0000) knlGS:0000000000000000
[41958.710628] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[41958.710630] CR2: 0000000000000000 CR3: 0000000002c09002 CR4: 00000000001606f0
[41958.710633] Call Trace:
[41958.710636]  <IRQ>
[41958.710668]  __i915_request_submit+0x12b/0x160 [i915]
[41958.710693]  virtual_submit_request+0x67/0x120 [i915]
[41958.710720]  __unwind_incomplete_requests+0x131/0x170 [i915]
[41958.710744]  execlists_dequeue+0xb40/0xe00 [i915]
[41958.710771]  execlists_submission_tasklet+0x10f/0x150 [i915]
[41958.710776]  tasklet_action_common.isra.17+0x41/0xa0
[41958.710781]  __do_softirq+0xc8/0x221
[41958.710785]  irq_exit+0xa6/0xb0
[41958.710788]  smp_apic_timer_interrupt+0x4d/0x80
[41958.710791]  apic_timer_interrupt+0xf/0x20
[41958.710794]  </IRQ>

Fixes: cb2377a919 ("drm/i915: Fixup preempt-to-busy vs reset of a virtual request")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191001103518.9113-1-chris@chris-wilson.co.uk
2019-10-01 11:46:52 +01:00
Documentation drm/i915/dsb: Documentation for DSB. 2019-09-23 10:21:54 +03:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch - More changes on simplifying locking mechanisms (Chris) 2019-08-06 12:49:12 +10:00
block for-linus-20190726-2 2019-07-26 19:20:34 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
drivers drm/i915: Initialise breadcrumb lists on the virtual engine 2019-10-01 11:46:52 +01:00
fs Merge tag 'xfs-5.3-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux 2019-08-03 10:43:44 -07:00
include drm/i915/tgl: s/ss/eu fuse reading support 2019-09-21 08:31:08 +01:00
init Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
ipc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
kernel memremap: move from kernel/ to mm/ 2019-08-03 07:02:01 -07:00
lib Kbuild fixes for v5.3 (2nd) 2019-08-04 10:16:30 -07:00
mm memremap: move from kernel/ to mm/ 2019-08-03 07:02:01 -07:00
net tcp: be more careful in tcp_fragment() 2019-07-21 20:41:24 -07:00
samples treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers again 2019-07-25 11:05:10 +02:00
scripts kconfig: Clear "written" flag to avoid data loss 2019-08-04 12:44:15 +09:00
security selinux/stable-5.3 PR 20190801 2019-08-02 18:40:49 -07:00
sound sound fixes for 5.3-rc3 2019-08-02 08:53:34 -07:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-08-03 10:58:46 -07:00
usr kbuild: enable arch/s390/include/uapi/asm/zcrypt.h for uapi header test 2019-07-23 10:45:46 +02:00
virt Documentation: move Documentation/virtual to Documentation/virt 2019-07-24 10:52:11 +02:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore .gitignore: Add compilation database file 2019-07-27 12:18:19 +09:00
.mailmap MAINTAINERS: Update my email address 2019-07-22 14:57:50 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Remove references to dead website. 2019-07-19 12:22:04 -07:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS drm-misc-next for 5.4: 2019-08-21 16:44:41 +10:00
Makefile Linux 5.3-rc3 2019-08-04 18:40:12 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.