From a47734758145adf3655e1a8928b3a377c4d770f2 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 10 Jan 2020 12:30:59 +0000
Subject: drm/i915: Drop request list from error state
Git-commit: 1a8585bd774c4058038ad827c9e93847ff509cf3
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

The list of requests from after the hang tells little about the hang
itself, only how busy userspace was after the fact. As it pertains
nothing to the HW state, drop it from the error state.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110123059.1348712-4-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/i915_gpu_error.c | 75 +++------------------------
 drivers/gpu/drm/i915/i915_gpu_error.h |  3 +-
 2 files changed, 8 insertions(+), 70 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 73884a189859..4c1836f0a991 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -669,7 +669,7 @@ static void err_print_gt(struct drm_i915_error_state_buf *m,
 			 struct intel_gt_coredump *gt)
 {
 	const struct intel_engine_coredump *ee;
-	int i, j;
+	int i;
 
 	err_printf(m, "GT awake: %s\n", yesno(gt->awake));
 	err_printf(m, "EIR: 0x%08x\n", gt->eir);
@@ -715,17 +715,8 @@ static void err_print_gt(struct drm_i915_error_state_buf *m,
 		const struct i915_vma_coredump *vma;
 
 		error_print_engine(m, ee);
-
 		for (vma = ee->vma; vma; vma = vma->next)
 			print_error_vma(m, ee->engine, vma);
-
-		if (ee->num_requests) {
-			err_printf(m, "%s --- %d requests\n",
-				   ee->engine->name,
-				   ee->num_requests);
-			for (j = 0; j < ee->num_requests; j++)
-				error_print_request(m, " ", &ee->requests[j]);
-		}
 	}
 
 	if (gt->uc)
@@ -936,7 +927,6 @@ static void cleanup_gt(struct intel_gt_coredump *gt)
 		gt->engine = ee->next;
 
 		i915_vma_coredump_free(ee->vma);
-		kfree(ee->requests);
 		kfree(ee);
 	}
 
@@ -1221,54 +1211,6 @@ static void record_request(const struct i915_request *request,
 	rcu_read_unlock();
 }
 
-static void engine_record_requests(const struct intel_engine_cs *engine,
-				   struct i915_request *first,
-				   struct intel_engine_coredump *ee)
-{
-	struct i915_request *request;
-	int count;
-
-	count = 0;
-	request = first;
-	list_for_each_entry_from(request, &engine->active.requests, sched.link)
-		count++;
-	if (!count)
-		return;
-
-	ee->requests = kcalloc(count, sizeof(*ee->requests), ATOMIC_MAYFAIL);
-	if (!ee->requests)
-		return;
-
-	ee->num_requests = count;
-
-	count = 0;
-	request = first;
-	list_for_each_entry_from(request,
-				 &engine->active.requests, sched.link) {
-		if (count >= ee->num_requests) {
-			/*
-			 * If the ring request list was changed in
-			 * between the point where the error request
-			 * list was created and dimensioned and this
-			 * point then just exit early to avoid crashes.
-			 *
-			 * We don't need to communicate that the
-			 * request list changed state during error
-			 * state capture and that the error state is
-			 * slightly incorrect as a consequence since we
-			 * are typically only interested in the request
-			 * list state at the point of error state
-			 * capture, not in any changes happening during
-			 * the capture.
-			 */
-			break;
-		}
-
-		record_request(request, &ee->requests[count++]);
-	}
-	ee->num_requests = count;
-}
-
 static void engine_record_execlists(struct intel_engine_coredump *ee)
 {
 	const struct intel_engine_execlists * const el = &ee->engine->execlists;
@@ -1480,7 +1422,7 @@ static struct intel_engine_coredump *
 capture_engine(struct intel_engine_cs *engine,
 	       struct i915_vma_compress *compress)
 {
-	struct intel_engine_capture_vma *capture;
+	struct intel_engine_capture_vma *capture = NULL;
 	struct intel_engine_coredump *ee;
 	struct i915_request *rq;
 	unsigned long flags;
@@ -1490,19 +1432,16 @@ capture_engine(struct intel_engine_cs *engine,
 		return NULL;
 
 	spin_lock_irqsave(&engine->active.lock, flags);
-
 	rq = intel_engine_find_active_request(engine);
-	if (!rq) {
-		spin_unlock_irqrestore(&engine->active.lock, flags);
+	if (rq)
+		capture = intel_engine_coredump_add_request(ee, rq,
+							    ATOMIC_MAYFAIL);
+	spin_unlock_irqrestore(&engine->active.lock, flags);
+	if (!capture) {
 		kfree(ee);
 		return NULL;
 	}
 
-	capture = intel_engine_coredump_add_request(ee, rq, ATOMIC_MAYFAIL);
-	engine_record_requests(engine, rq, ee);
-
-	spin_unlock_irqrestore(&engine->active.lock, flags);
-
 	intel_engine_coredump_add_vma(ee, capture, compress);
 
 	return ee;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h
index 8f4579d64d8c..b87f39291c07 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.h
+++ b/drivers/gpu/drm/i915/i915_gpu_error.h
@@ -60,7 +60,6 @@ struct intel_engine_coredump {
 	const struct intel_engine_cs *engine;
 
 	bool simulated;
-	int num_requests;
 	u32 reset_count;
 
 	/* position of active request inside the ring */
@@ -96,7 +95,7 @@ struct intel_engine_coredump {
 
 	struct i915_vma_coredump *vma;
 
-	struct i915_request_coredump *requests, execlist[EXECLIST_MAX_PORTS];
+	struct i915_request_coredump execlist[EXECLIST_MAX_PORTS];
 	unsigned int num_ports;
 
 	struct {
-- 
2.28.0