[Intel-gfx] [PATCH 1/5] drm/i915/error: capture execlist state on error

[Chris Wilson]

On Fri, Jan 29, 2016 at 12:25:02PM +0000, Arun Siluvery wrote:
> On 29/01/2016 11:45, Chris Wilson wrote:
> >On Fri, Jan 29, 2016 at 09:49:07AM +0200, Mika Kuoppala wrote:
> >>Arun Siluvery <arun.siluvery at linux.intel.com> writes:
> >>
> >>>From: Dave Gordon <david.s.gordon at intel.com>
> >>>
> >>>At present, execlist status/ctx_id and CSBs, not the submission queue
> >>>
> >>>For: VIZ-2021
> >>>Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
> >>>---
> >>>  drivers/gpu/drm/i915/i915_drv.h       |  9 +++++++++
> >>>  drivers/gpu/drm/i915/i915_gpu_error.c | 38 +++++++++++++++++++++++++++++++++--
> >>>  2 files changed, 45 insertions(+), 2 deletions(-)
> >>>
> >>>diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> >>>index 01cc982..8b30242 100644
> >>>--- a/drivers/gpu/drm/i915/i915_drv.h
> >>>+++ b/drivers/gpu/drm/i915/i915_drv.h
> >>>@@ -552,6 +552,15 @@ struct drm_i915_error_state {
> >>>  		u32 rc_psmi; /* sleep state */
> >>>  		u32 semaphore_mboxes[I915_NUM_RINGS - 1];
> >>>
> >>>+		/* Execlists */
> >>>+		u32 execlist_status;
> >>>+		u32 execlist_ctx_id;
> >>>+		u32 execlist_csb_raw_pointer;
> >>>+		u32 execlist_csb_write_pointer;
> >>>+		u32 execlist_csb_read_pointer;
> >>>+		u32 execlist_csb[6];
> >>>+		u32 execlist_ctx[6];
> >>>+
> >>>  		struct drm_i915_error_object {
> >>>  			int page_count;
> >>>  			u64 gtt_offset;
> >>>diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> >>>index 978c026..bf53c2b 100644
> >>>--- a/drivers/gpu/drm/i915/i915_gpu_error.c
> >>>+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> >>>@@ -247,6 +247,7 @@ static void i915_ring_error_state(struct drm_i915_error_state_buf *m,
> >>>  				  int ring_idx)
> >>>  {
> >>>  	struct drm_i915_error_ring *ring = &error->ring[ring_idx];
> >>>+	int i;
> >>>
> >>>  	if (!ring->valid)
> >>>  		return;
> >>>@@ -288,7 +289,6 @@ static void i915_ring_error_state(struct drm_i915_error_state_buf *m,
> >>>  		err_printf(m, "  GFX_MODE: 0x%08x\n", ring->vm_info.gfx_mode);
> >>>
> >>>  		if (INTEL_INFO(dev)->gen >= 8) {
> >>>-			int i;
> >>>  			for (i = 0; i < 4; i++)
> >>>  				err_printf(m, "  PDP%d: 0x%016llx\n",
> >>>  					   i, ring->vm_info.pdp[i]);
> >>>@@ -304,6 +304,17 @@ static void i915_ring_error_state(struct drm_i915_error_state_buf *m,
> >>>  	err_printf(m, "  hangcheck: %s [%d]\n",
> >>>  		   hangcheck_action_to_str(ring->hangcheck_action),
> >>>  		   ring->hangcheck_score);
> >>>+
> >>>+	err_printf(m, "  EXECLIST_STATUS: 0x%08x\n", ring->execlist_status);
> >>>+	err_printf(m, "  EXECLIST_CTX_ID: 0x%08x\n", ring->execlist_ctx_id);
> >>>+	err_printf(m, "  EXECLIST_CSBPTR: 0x%08x\n", ring->execlist_csb_raw_pointer);
> >>>+	err_printf(m, "  EXECLIST_CSB_WR: 0x%08x\n", ring->execlist_csb_write_pointer);
> >>>+	err_printf(m, "  EXECLIST_CSB_RD: 0x%08x\n", ring->execlist_csb_read_pointer);
> >>>+
> >>>+	for (i = 0; i < 6; i++) {
> >>>+		err_printf(m, "  EXECLIST_CSB[%d]: 0x%08x\n", i, ring->execlist_csb[i]);
> >>>+		err_printf(m, "  EXECLIST_CTX[%d]: 0x%08x\n", i, ring->execlist_ctx[i]);
> >>>+	}
> >>
> >>Please output only if i915.enable_execlists.
> >>
> >>>  }
> >>>
> >>>  void i915_error_printf(struct drm_i915_error_state_buf *e, const char *f, ...)
> >>>@@ -965,8 +976,27 @@ static void i915_record_ring_state(struct drm_device *dev,
> >>>  					I915_READ(GEN8_RING_PDP_LDW(ring, i));
> >>>  			}
> >>>  	}
> >>>-}
> >>>
> >>>+	if (i915.enable_execlists) {
> >>>+		int i;
> >>>+		u32 status_pointer = I915_READ(RING_CONTEXT_STATUS_PTR(ring));
> >>>+		u8 write_pointer = status_pointer & 0x07;
> >>>+		u8 read_pointer = ring->next_context_status_buffer;
> >>>+		if (read_pointer > write_pointer)
> >>>+			write_pointer += 6;
> >>>+
> >>>+		ering->execlist_status = I915_READ(RING_EXECLIST_STATUS_LO(ring));
> >>>+		ering->execlist_ctx_id = I915_READ(RING_EXECLIST_STATUS_HI(ring));
> >>>+		ering->execlist_csb_raw_pointer = status_pointer;
> >>>+		ering->execlist_csb_write_pointer = write_pointer;
> >>>+		ering->execlist_csb_read_pointer = read_pointer;
> >
> >Just the registers. How do you plan to use these to debug anything?
> csb pointers are helpful when there is an inconsistency between sw
> and hw which can happen if we miss ctx switch interrupts.

Yes, but you are printing them twice. (next_context_status_buffer can be
shot btw)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre