Take a wakeref on the intel_gt specifically for the enabled breadcrumb
interrupt so that we can safely process the mmio. If the intel_gt is
already asleep by the time we try and setup the breadcrumb interrupt, by
a process of elimination we know the request must have been completed
and we can skip its enablement!
<4> [1518.350005] Unclaimed write to register 0x220a8
<4> [1518.350323] WARNING: CPU: 2 PID: 3685 at drivers/gpu/drm/i915/intel_uncore.c:1163 __unclaimed_reg_debug+0x40/0x50 [i915]
<4> [1518.350393] Modules linked in: vgem snd_hda_codec_hdmi x86_pkg_temp_thermal i915 coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core btusb cdc_ether btrtl usbnet btbcm btintel r8152 snd_pcm mii bluetooth ecdh_generic ecc i2c_hid pinctrl_sunrisepoint pinctrl_intel intel_lpss_pci prime_numbers [last unloaded: vgem]
<4> [1518.350646] CPU: 2 PID: 3685 Comm: gem_exec_parse_ Tainted: G U 5.4.0-rc8-CI-CI_DRM_7490+ #1
<4> [1518.350708] Hardware name: Google Caroline/Caroline, BIOS MrChromebox 08/27/2018
<4> [1518.350946] RIP: 0010:__unclaimed_reg_debug+0x40/0x50 [i915]
<4> [1518.350992] Code: 74 05 5b 5d 41 5c c3 45 84 e4 48 c7 c0 95 8d 47 a0 48 c7 c6 8b 8d 47 a0 48 0f 44 f0 89 ea 48 c7 c7 9e 8d 47 a0 e8 40 45 e3 e0 <0f> 0b 83 2d 27 4f 2a 00 01 5b 5d 41 5c c3 66 90 41 55 41 54 55 53
<4> [1518.351100] RSP: 0018:ffffc900007f39c8 EFLAGS: 00010086
<4> [1518.351140] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
<4> [1518.351202] RDX: 0000000080000006 RSI: 0000000000000000 RDI: 00000000ffffffff
<4> [1518.351249] RBP: 00000000000220a8 R08: 0000000000000000 R09: 0000000000000000
<4> [1518.351296] R10: ffffc900007f3990 R11: ffffc900007f3868 R12: 0000000000000000
<4> [1518.351342] R13: 00000000fefeffff R14: 0000000000000092 R15: ffff888155fea000
<4> [1518.351391] FS: 00007fc255abfe40(0000) GS:ffff88817ab00000(0000) knlGS:0000000000000000
<4> [1518.351445] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [1518.351485] CR2: 00007fc2554882d0 CR3: 0000000168ca2005 CR4: 00000000003606e0
<4> [1518.351529] Call Trace:
<4> [1518.351746] fwtable_write32+0x114/0x1d0 [i915]
<4> [1518.351795] ? sync_file_alloc+0x80/0x80
<4> [1518.352039] gen8_logical_ring_enable_irq+0x30/0x50 [i915]
<4> [1518.352295] irq_enable.part.10+0x23/0x40 [i915]
<4> [1518.352523] i915_request_enable_breadcrumb+0xb5/0x330 [i915]
<4> [1518.352575] ? sync_file_alloc+0x80/0x80
<4> [1518.352612] __dma_fence_enable_signaling+0x60/0x160
<4> [1518.352653] ? sync_file_alloc+0x80/0x80
<4> [1518.352685] dma_fence_add_callback+0x44/0xd0
<4> [1518.352726] sync_file_poll+0x95/0xc0
<4> [1518.352767] do_sys_poll+0x24d/0x570
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 22 +++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
index 55317081d48b..8a9facf4f3b6 100644
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
@@ -28,6 +28,7 @@
#include "i915_drv.h"
#include "i915_trace.h"
+#include "intel_gt_pm.h"
static void irq_enable(struct intel_engine_cs *engine)
{
@@ -53,15 +54,17 @@ static void irq_disable(struct intel_engine_cs *engine)
static void __intel_breadcrumbs_disarm_irq(struct intel_breadcrumbs *b)
{
+ struct intel_engine_cs *engine =
+ container_of(b, struct intel_engine_cs, breadcrumbs);
+
lockdep_assert_held(&b->irq_lock);
GEM_BUG_ON(!b->irq_enabled);
if (!--b->irq_enabled)
- irq_disable(container_of(b,
- struct intel_engine_cs,
- breadcrumbs));
+ irq_disable(engine);
b->irq_armed = false;
+ intel_gt_pm_put_async(engine->gt);
}
void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine)
@@ -207,14 +210,17 @@ static void signal_irq_work(struct irq_work *work)
intel_engine_breadcrumbs_irq(engine);
}
-static void __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
+static bool __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
{
struct intel_engine_cs *engine =
container_of(b, struct intel_engine_cs, breadcrumbs);
lockdep_assert_held(&b->irq_lock);
if (b->irq_armed)
- return;
+ return true;
+
+ if (!intel_gt_pm_get_if_awake(engine->gt))
+ return false;
/*
* The breadcrumb irq will be disarmed on the interrupt after the
@@ -234,6 +240,8 @@ static void __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
if (!b->irq_enabled++)
irq_enable(engine);
+
+ return true;
}
void intel_engine_init_breadcrumbs(struct intel_engine_cs *engine)
@@ -277,7 +285,8 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq)
spin_lock(&b->irq_lock);
GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags));
- __intel_breadcrumbs_arm_irq(b);
+ if (!__intel_breadcrumbs_arm_irq(b))
+ goto unlock;
/*
* We keep the seqno in retirement order, so we can break
@@ -306,6 +315,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq)
GEM_BUG_ON(!check_signal_order(ce, rq));
set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
+unlock:
spin_unlock(&b->irq_lock);
}
