9a4dc80399
Inside the live_hangcheck (reset) selftests, we occasionally see failures like <7>[ 239.094840] i915_gem_set_wedged rcs0 <7>[ 239.094843] i915_gem_set_wedged current seqno 19a98, last 19a9a, hangcheck 0 [5158 ms] <7>[ 239.094846] i915_gem_set_wedged Reset count: 6239 (global 1) <7>[ 239.094848] i915_gem_set_wedged Requests: <7>[ 239.095052] i915_gem_set_wedged first 19a99 [e8c:5f] prio=1024 @ 5159ms: (null) <7>[ 239.095056] i915_gem_set_wedged last 19a9a [e81:1a] prio=139 @ 5159ms: igt/rcs0[5977]/1 <7>[ 239.095059] i915_gem_set_wedged active 19a99 [e8c:5f] prio=1024 @ 5159ms: (null) <7>[ 239.095062] i915_gem_set_wedged [head 0220, postfix 0280, tail 02a8, batch 0xffffffff_ffffffff] <7>[ 239.100050] i915_gem_set_wedged ring->start: 0x00283000 <7>[ 239.100053] i915_gem_set_wedged ring->head: 0x000001f8 <7>[ 239.100055] i915_gem_set_wedged ring->tail: 0x000002a8 <7>[ 239.100057] i915_gem_set_wedged ring->emit: 0x000002a8 <7>[ 239.100059] i915_gem_set_wedged ring->space: 0x00000f10 <7>[ 239.100085] i915_gem_set_wedged RING_START: 0x00283000 <7>[ 239.100088] i915_gem_set_wedged RING_HEAD: 0x00000260 <7>[ 239.100091] i915_gem_set_wedged RING_TAIL: 0x000002a8 <7>[ 239.100094] i915_gem_set_wedged RING_CTL: 0x00000001 <7>[ 239.100097] i915_gem_set_wedged RING_MODE: 0x00000300 [idle] <7>[ 239.100100] i915_gem_set_wedged RING_IMR: fffffefe <7>[ 239.100104] i915_gem_set_wedged ACTHD: 0x00000000_0000609c <7>[ 239.100108] i915_gem_set_wedged BBADDR: 0x00000000_0000609d <7>[ 239.100111] i915_gem_set_wedged DMA_FADDR: 0x00000000_00283260 <7>[ 239.100114] i915_gem_set_wedged IPEIR: 0x00000000 <7>[ 239.100117] i915_gem_set_wedged IPEHR: 0x02800000 <7>[ 239.100120] i915_gem_set_wedged Execlist status: 0x00044052 00000002 <7>[ 239.100124] i915_gem_set_wedged Execlist CSB read 5 [5 cached], write 5 [5 from hws], interrupt posted? no, tasklet queued? no (enabled) <7>[ 239.100128] i915_gem_set_wedged ELSP[0] count=1, ring->start=00283000, rq: 19a99 [e8c:5f] prio=1024 @ 5164ms: (null) <7>[ 239.100132] i915_gem_set_wedged ELSP[1] count=1, ring->start=00257000, rq: 19a9a [e81:1a] prio=139 @ 5164ms: igt/rcs0[5977]/1 <7>[ 239.100135] i915_gem_set_wedged HW active? 0x5 <7>[ 239.100250] i915_gem_set_wedged E 19a99 [e8c:5f] prio=1024 @ 5164ms: (null) <7>[ 239.100338] i915_gem_set_wedged E 19a9a [e81:1a] prio=139 @ 5164ms: igt/rcs0[5977]/1 <7>[ 239.100340] i915_gem_set_wedged Queue priority: 139 <7>[ 239.100343] i915_gem_set_wedged Q 0 [e98:19] prio=132 @ 5164ms: igt/rcs0[5977]/8 <7>[ 239.100346] i915_gem_set_wedged Q 0 [e84:19] prio=121 @ 5165ms: igt/rcs0[5977]/2 <7>[ 239.100349] i915_gem_set_wedged Q 0 [e87:19] prio=82 @ 5165ms: igt/rcs0[5977]/3 <7>[ 239.100352] i915_gem_set_wedged Q 0 [e84:1a] prio=44 @ 5164ms: igt/rcs0[5977]/2 <7>[ 239.100356] i915_gem_set_wedged Q 0 [e8b:19] prio=20 @ 5165ms: igt/rcs0[5977]/4 <7>[ 239.100362] i915_gem_set_wedged drv_selftest [5894] waiting for 19a99 where the GPU saw an arbitration point and idles; AND HAS NOT BEEN RESET! The RING_MODE indicates that is idle and has the STOP_RING bit set, so try clearing it. v2: Only clear the bit on restarting the ring, as we want to be sure the STOP_RING bit is kept if reset fails on wedging. v3: Spot when the ring state doesn't make sense when re-initialising the engine and dump it to the logs so that we don't have to wait for an error later and try to guess what happened earlier. v4: Prepare to print all the unexpected state, not just the first. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180518100933.2239-1-chris@chris-wilson.co.uk
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.
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.