patch 'dma/skeleton: fix index returned when no memcpy completed' has been queued to stable release 21.11.2

[Kevin Traynor <ktraynor@redhat.com>]

Hi,

FYI, your patch has been queued to stable release 21.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/23/22. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/e027f40cd22e85c1790a12d8441c8659025fc228

Thanks.

Kevin

---
From e027f40cd22e85c1790a12d8441c8659025fc228 Mon Sep 17 00:00:00 2001
From: Chengwen Feng <fengchengwen@huawei.com>
Date: Wed, 8 Jun 2022 16:50:05 +0800
Subject: [PATCH] dma/skeleton: fix index returned when no memcpy completed

[ upstream commit 618a40a0c97f4e80b05d2dce4d63eecc6210a242 ]

If no memcopy request is completed, the ring_idx of the last completed
operation need returned by last_idx parameter. This patch fixes it.

Fixes: 05d5fc66a269 ("dma/skeleton: introduce skeleton driver")

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
---
 drivers/dma/skeleton/skeleton_dmadev.c | 17 ++++++++++++++---
 drivers/dma/skeleton/skeleton_dmadev.h |  1 +
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/skeleton/skeleton_dmadev.c b/drivers/dma/skeleton/skeleton_dmadev.c
index 81cbdd286e..6b0bb14e2c 100644
--- a/drivers/dma/skeleton/skeleton_dmadev.c
+++ b/drivers/dma/skeleton/skeleton_dmadev.c
@@ -119,4 +119,5 @@ skeldma_start(struct rte_dma_dev *dev)
 	fflush_ring(hw, hw->desc_completed);
 	hw->ridx = 0;
+	hw->last_ridx = hw->ridx - 1;
 	hw->submitted_count = 0;
 	hw->zero_req_count = 0;
@@ -323,7 +324,9 @@ skeldma_dump(const struct rte_dma_dev *dev, FILE *f)
 	(void)fprintf(f,
 		"    next_ring_idx: %u\n"
+		"    last_ring_idx: %u\n"
 		"    submitted_count: %" PRIu64 "\n"
 		"    completed_count: %" PRIu64 "\n",
-		hw->ridx, hw->submitted_count, hw->completed_count);
+		hw->ridx, hw->last_ridx,
+		hw->submitted_count, hw->completed_count);
 
 	return 0;
@@ -399,9 +402,13 @@ skeldma_completed(void *dev_private,
 	while (index < count) {
 		(void)rte_ring_dequeue(hw->desc_completed, (void **)&desc);
-		if (index == count - 1)
+		if (index == count - 1) {
+			hw->last_ridx = desc->ridx;
 			*last_idx = desc->ridx;
+		}
 		index++;
 		(void)rte_ring_enqueue(hw->desc_empty, (void *)desc);
 	}
+	if (unlikely(count == 0))
+		*last_idx = hw->last_ridx;
 
 	return count;
@@ -423,9 +430,13 @@ skeldma_completed_status(void *dev_private,
 	while (index < count) {
 		(void)rte_ring_dequeue(hw->desc_completed, (void **)&desc);
-		if (index == count - 1)
+		if (index == count - 1) {
+			hw->last_ridx = desc->ridx;
 			*last_idx = desc->ridx;
+		}
 		status[index++] = RTE_DMA_STATUS_SUCCESSFUL;
 		(void)rte_ring_enqueue(hw->desc_empty, (void *)desc);
 	}
+	if (unlikely(count == 0))
+		*last_idx = hw->last_ridx;
 
 	return count;
diff --git a/drivers/dma/skeleton/skeleton_dmadev.h b/drivers/dma/skeleton/skeleton_dmadev.h
index 91eb5460fc..6f89400480 100644
--- a/drivers/dma/skeleton/skeleton_dmadev.h
+++ b/drivers/dma/skeleton/skeleton_dmadev.h
@@ -51,4 +51,5 @@ struct skeldma_hw {
 	char cache1 __rte_cache_aligned;
 	uint16_t ridx;  /* ring idx */
+	uint16_t last_ridx;
 	uint64_t submitted_count;
 
-- 
2.34.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-06-20 10:46:28.169434815 +0100
+++ 0018-dma-skeleton-fix-index-returned-when-no-memcpy-compl.patch	2022-06-20 10:46:27.796146856 +0100
@@ -1 +1 @@
-From 618a40a0c97f4e80b05d2dce4d63eecc6210a242 Mon Sep 17 00:00:00 2001
+From e027f40cd22e85c1790a12d8441c8659025fc228 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 618a40a0c97f4e80b05d2dce4d63eecc6210a242 ]
+
@@ -10 +11,0 @@
-Cc: stable@dpdk.org