The HW watchdog exists for all the rings. It's just a register, but if
we writing in the command stream it has the effect we want of generating
interrupts if a given batch is taking too long.
Unfortunately, our hardware doesn't support interrupts on the blit ring.
We still need the software watchdog for that.
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/i915_drv.h | 2 +-
drivers/gpu/drm/i915/i915_reg.h | 2 ++
drivers/gpu/drm/i915/intel_ringbuffer.c | 26 +++++++++++++++++++++++++-
3 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 627fe35..0a13b22 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -430,7 +430,7 @@ typedef struct drm_i915_private {
int num_pch_pll;
/* For hangcheck timer */
-#define DRM_I915_HANGCHECK_PERIOD 1500 /* in ms */
+#define DRM_I915_HANGCHECK_PERIOD 3000 /* in ms */
struct timer_list hangcheck_timer;
int hangcheck_count;
uint32_t last_acthd[I915_NUM_RINGS];
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index cc82871..195154b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -449,6 +449,8 @@
#define RING_ACTHD(base) ((base)+0x74)
#define RING_NOPID(base) ((base)+0x94)
#define RING_IMR(base) ((base)+0xa8)
+#define RING_WATCHDOG_CTL(base) ((base)+0x178)
+#define RING_WATCHDOG_THRESH(base) ((base)+0x17c)
#define TAIL_ADDR 0x001FFFF8
#define HEAD_WRAP_COUNT 0xFFE00000
#define HEAD_WRAP_ONE 0x00200000
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ddc4859..f61b4a0 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1038,6 +1038,9 @@ static int intel_init_ring_buffer(struct drm_device *dev,
goto err_unpin;
}
+ I915_WRITE(RING_WATCHDOG_CTL(ring->mmio_base), UINT_MAX);
+ I915_WRITE(RING_WATCHDOG_THRESH(ring->mmio_base), UINT_MAX);
+
ret = ring->init(ring);
if (ret)
goto err_unmap;
@@ -1318,19 +1321,40 @@ static int gen6_ring_flush(struct intel_ring_buffer *ring,
return 0;
}
+#define PERIOD_NS 80
+#define WATCHDOG_TIMEOUT(timeout_ms) (DIV_ROUND_UP(timeout_ms * NSEC_PER_MSEC, PERIOD_NS))
+/* this should be less than the i915 software watchdog */
+#define DEFAULT_WATCHDOG_TIMEOUT WATCHDOG_TIMEOUT(DRM_I915_HANGCHECK_PERIOD / 2)
+
static int
gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
u32 offset, u32 len)
{
int ret;
- ret = intel_ring_begin(ring, 2);
+ ret = intel_ring_begin(ring, 14);
if (ret)
return ret;
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, RING_WATCHDOG_THRESH(ring->mmio_base));
+ intel_ring_emit(ring, DEFAULT_WATCHDOG_TIMEOUT);
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, RING_WATCHDOG_CTL(ring->mmio_base));
+ intel_ring_emit(ring, 0);
+
+ /* add breadcrumb here */
+
intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_NON_SECURE_I965);
/* bit0-7 is the length on GEN6+ */
intel_ring_emit(ring, offset);
+
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, RING_WATCHDOG_CTL(ring->mmio_base));
+ intel_ring_emit(ring, UINT_MAX);
+
intel_ring_advance(ring);
return 0;
--
1.7.11.2
