From ee283c0d1206fda21fcd82255a9ea8df194e6470 Mon Sep 17 00:00:00 2001
From: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Date: Thu, 5 Aug 2021 16:09:55 +0200
Subject: [PATCH] gpu/intel: dump more in error case

- show hardware read tail & head pointer of ring buffer

issue #4254
---
 repos/os/src/drivers/gpu/intel/context.h     |  5 +++++
 repos/os/src/drivers/gpu/intel/main.cc       |  8 +++++---
 repos/os/src/drivers/gpu/intel/ring_buffer.h | 10 +++++++---
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/repos/os/src/drivers/gpu/intel/context.h b/repos/os/src/drivers/gpu/intel/context.h
index a6fd31e9b6..4ecb7caa1f 100644
--- a/repos/os/src/drivers/gpu/intel/context.h
+++ b/repos/os/src/drivers/gpu/intel/context.h
@@ -821,6 +821,11 @@ class Igd::Rcs_context
 			_execlist_context.tail_offset(offset);
 		}
 
+		addr_t tail_offset()
+		{
+			return _execlist_context.tail_offset();
+		}
+
 		/*********************
 		 ** Debug interface **
 		 *********************/
diff --git a/repos/os/src/drivers/gpu/intel/main.cc b/repos/os/src/drivers/gpu/intel/main.cc
index 96e0111c0f..710cf96318 100644
--- a/repos/os/src/drivers/gpu/intel/main.cc
+++ b/repos/os/src/drivers/gpu/intel/main.cc
@@ -329,7 +329,7 @@ struct Igd::Device
 			_ring.flush(from, to);
 		}
 
-		void ring_dump(size_t limit = 0) const { _ring.dump(limit); }
+		void ring_dump(size_t limit, unsigned hw_tail, unsigned hw_head) const { _ring.dump(limit, hw_tail, hw_head); }
 
 		/*********************
 		 ** Debug interface **
@@ -891,8 +891,10 @@ struct Igd::Device
 
 		_active_vgpu->rcs.context->dump();
 		_active_vgpu->rcs.context->dump_hw_status_page();
-		Execlist const &el = *_active_vgpu->rcs.execlist;
-		el.ring_dump(52);
+		Execlist &el = *_active_vgpu->rcs.execlist;
+		el.ring_update_head(_active_vgpu->rcs.context->head_offset());
+		el.ring_dump(4096, _active_vgpu->rcs.context->tail_offset() * 2,
+		                   _active_vgpu->rcs.context->head_offset());
 
 		_device_reset_and_init();
 
diff --git a/repos/os/src/drivers/gpu/intel/ring_buffer.h b/repos/os/src/drivers/gpu/intel/ring_buffer.h
index 5f9ffefeb5..2b526911bf 100644
--- a/repos/os/src/drivers/gpu/intel/ring_buffer.h
+++ b/repos/os/src/drivers/gpu/intel/ring_buffer.h
@@ -186,19 +186,23 @@ class Igd::Ring_buffer
 		 ** Debug interface **
 		 *********************/
 
-		void dump(size_t dw_limit = 0) const
+		void dump(size_t dw_limit, unsigned const hw_tail, unsigned const hw_head) const
 		{
 			using namespace Genode;
 
 			size_t const max = dw_limit ? dw_limit : _max;
 
-			log("Ring_buffer: ", Hex(*_dwords), " max: ", _max, " (limit: ", max, ")");
+			log("Ring_buffer: ", Hex(*_dwords), " max: ", _max, " (limit: ", max, ")",
+			    " hardware read: tail=", Genode::Hex(hw_tail),
+			    " head=", Genode::Hex(hw_head));
 
 			for (size_t i = 0; i < max; i++) {
 				log(Hex(i*4, Hex::PREFIX, Hex::PAD), " ",
 				    Hex(_dwords[i], Hex::PREFIX, Hex::PAD),
 				    i == _tail ? " T " : "   ",
-				    i == _head ? " H " : "   "
+				    i == _head ? " H " : "   ",
+				    i == hw_tail ? " T_HW " : "   ",
+				    i == hw_head ? " H_HW " : "   "
 				);
 			}
 		}