[PATCH 1/5] thunderbolt: stream: Restore consumer if copying from iter fails

[Mika Westerberg <mika.westerberg@linux.intel.com>]

In tbstream_dev_alloc_tx() if copying data from iterator fails we leave
the consumer pointer as is wasting one entry in the ring. Fix this by
restoring the consumer back in case of failure.

Fixes: 6db21d817b43 ("thunderbolt: Add support for USB4STREAM")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/stream.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/stream.c b/drivers/thunderbolt/stream.c
index c1f5c55583d0..279a0cfc2ac8 100644
--- a/drivers/thunderbolt/stream.c
+++ b/drivers/thunderbolt/stream.c
@@ -512,8 +512,10 @@ tbstream_dev_alloc_tx(struct tbstream_dev *sdev, enum tbstream_frame_pdf pdf,
 	dma_sync_single_for_cpu(dma_dev, sf->frame.buffer_phy, size,
 				DMA_TO_DEVICE);
 	if (pdf == TBSTREAM_DATA) {
-		if (copy_page_from_iter(sf->page, 0, size, from) != size)
+		if (copy_page_from_iter(sf->page, 0, size, from) != size) {
+			sdev->tx_ring.cons--;
 			return ERR_PTR(-EFAULT);
+		}
 	} else {
 		memset(page_address(sf->page), 0, size);
 	}
-- 
2.50.1