From 14a6bbf9e5359568f782a936c22a46502c258107 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 14 Mar 2017 11:14:52 +0000 Subject: [PATCH] drm/i915: Replace irq_seqno_barrier on hws write with a clflush 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 Link: http://patchwork.freedesktop.org/patch/msgid/20170314111452.9375-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala --- 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 73fe718516a5..36cbe4b5d7eb 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -248,8 +248,7 @@ 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 0ef491df5b4e..406188150c96 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -462,7 +462,11 @@ 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(); } /* -- 2.20.1