Thread (9 messages) 9 messages, 3 authors, 2020-07-31
STALE2140d

[PATCH net-next 4/4] s390/qeth: use all configured RX buffers

From: Julian Wiedmann <hidden>
Date: 2020-07-30 15:03:16
Also in: linux-s390
Subsystem: networking drivers, s390 architecture, s390 network drivers, the rest · Maintainers: Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Alexandra Winter, Aswin Karuvally, Linus Torvalds

The (misplaced) comment doesn't make any sense, enforcing an
uninitialized RX buffer won't help with IRQ reduction.

So make the best use of all available RX buffers.

Signed-off-by: Julian Wiedmann <redacted>
---
 drivers/s390/net/qeth_core_main.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index c2e44853ac1a..bba1b54b8aa3 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -3022,6 +3022,7 @@ static unsigned int qeth_tx_select_bulk_max(struct qeth_card *card,
 
 static int qeth_init_qdio_queues(struct qeth_card *card)
 {
+	unsigned int rx_bufs = card->qdio.in_buf_pool.buf_count;
 	unsigned int i;
 	int rc;
 
@@ -3033,16 +3034,14 @@ static int qeth_init_qdio_queues(struct qeth_card *card)
 
 	qeth_initialize_working_pool_list(card);
 	/*give only as many buffers to hardware as we have buffer pool entries*/
-	for (i = 0; i < card->qdio.in_buf_pool.buf_count - 1; i++) {
+	for (i = 0; i < rx_bufs; i++) {
 		rc = qeth_init_input_buffer(card, &card->qdio.in_q->bufs[i]);
 		if (rc)
 			return rc;
 	}
 
-	card->qdio.in_q->next_buf_to_init =
-		card->qdio.in_buf_pool.buf_count - 1;
-	rc = do_QDIO(CARD_DDEV(card), QDIO_FLAG_SYNC_INPUT, 0, 0,
-		     card->qdio.in_buf_pool.buf_count - 1);
+	card->qdio.in_q->next_buf_to_init = QDIO_BUFNR(rx_bufs);
+	rc = do_QDIO(CARD_DDEV(card), QDIO_FLAG_SYNC_INPUT, 0, 0, rx_bufs);
 	if (rc) {
 		QETH_CARD_TEXT_(card, 2, "1err%d", rc);
 		return rc;
@@ -3535,13 +3534,6 @@ static unsigned int qeth_rx_refill_queue(struct qeth_card *card,
 			return 0;
 		}
 
-		/*
-		 * according to old code it should be avoided to requeue all
-		 * 128 buffers in order to benefit from PCI avoidance.
-		 * this function keeps at least one buffer (the buffer at
-		 * 'index') un-requeued -> this buffer is the first buffer that
-		 * will be requeued the next time
-		 */
 		rc = do_QDIO(CARD_DDEV(card), QDIO_FLAG_SYNC_INPUT, 0,
 			     queue->next_buf_to_init, count);
 		if (rc) {
-- 
2.17.1
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