When manually overwriting the HWS, rather than assume irq_seqno_barrier
does the right thing, we can explicitly flush the cacheline instead.
This avoids us calling the engine->irq_seqno_barrier() from an illegal
context:
[ 1472.651797] BUG: scheduling while atomic: migration/0/11/0x00000002
[ 1472.651807] Modules linked in: ctr ccm arc4 snd_hda_codec_hdmi bnep rfcomm iwldvm snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel mac80211 snd_hda_codec snd_hda_core snd_pcm dm_multipath snd_hwdep intel_powerclamp coretemp snd_seq_midi crct10dif_pclmul snd_seq_midi_event crc32_pclmul iwlwifi ghash_clmulni_intel btusb snd_rawmidi btrtl aesni_intel btbcm aes_x86_64 crypto_simd btintel cryptd glue_helper bluetooth snd_seq cfg80211 snd_timer snd_seq_device intel_ips binfmt_misc snd mei_me soundcore mei dm_mirror dm_region_hash dm_log i915 intel_gtt i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea prime_numbers e1000e drm ahci libahci
[ 1472.651897] CPU: 0 PID: 11 Comm: migration/0 Tainted: G U 4.11.0-rc1+ #203
[ 1472.651899] Hardware name: LENOVO 514328U/514328U, BIOS 6QET44WW (1.14 ) 04/20/2010
[ 1472.651900] Call Trace:
[ 1472.651913] dump_stack+0x63/0x90
[ 1472.651922] __schedule_bug+0x5d/0x6b
[ 1472.651930] __schedule+0x46a/0x5f0
[ 1472.651934] schedule+0x38/0x90
[ 1472.651938] schedule_hrtimeout_range_clock+0x85/0x110
[ 1472.651945] ? hrtimer_init+0x10/0x10
[ 1472.651949] schedule_hrtimeout_range+0xe/0x10
[ 1472.651952] usleep_range+0x4d/0x60
[ 1472.652037] gen5_seqno_barrier+0x13/0x20 [i915]
[ 1472.652101] intel_engine_init_global_seqno+0xd7/0x160 [i915]
[ 1472.652160] __i915_gem_set_wedged_BKL+0xa0/0x180 [i915]
[ 1472.652166] multi_cpu_stop+0xbb/0xe0
[ 1472.652170] ? cpu_stop_queue_work+0x90/0x90
[ 1472.652174] cpu_stopper_thread+0x82/0x110
[ 1472.652179] smpboot_thread_fn+0x137/0x190
[ 1472.652184] kthread+0xf7/0x130
[ 1472.652187] ? sort_range+0x20/0x20
[ 1472.652191] ? kthread_park+0x90/0x90
[ 1472.652195] ret_from_fork+0x2c/0x40
Testcase: igt/gem_eio #ilk
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_engine_cs.c | 3 +--
drivers/gpu/drm/i915/intel_ringbuffer.h | 4 ++++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 5663ebab851f..074ecaae6daa 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -249,8 +249,7 @@ void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno)
}
intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
- if (engine->irq_seqno_barrier)
- engine->irq_seqno_barrier(engine);
+ clear_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted);
GEM_BUG_ON(i915_gem_active_isset(&engine->timeline->last_request));
engine->hangcheck.seqno = seqno;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 9011ae484bd5..bad5e455e815 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -468,7 +468,11 @@ static inline void
intel_write_status_page(struct intel_engine_cs *engine,
int reg, u32 value)
{
+ mb();
+ clflush(&engine->status_page.page_addr[reg]);
engine->status_page.page_addr[reg] = value;
+ clflush(&engine->status_page.page_addr[reg]);
+ mb();
}
/*
--
2.11.0
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