Initial commit

target/linux/ipq40xx/patches-6.6/711-net-qualcomm-ipqess-fix-TX-timeout-errors.patch

@@ -0,0 +1,64 @@
+From d0055b03d9c8d48ad2b971821989b09ba95c39f8 Mon Sep 17 00:00:00 2001
+From: Christian Marangi <ansuelsmth@gmail.com>
+Date: Sun, 17 Sep 2023 20:18:31 +0200
+Subject: [PATCH] net: qualcomm: ipqess: fix TX timeout errors
+
+Currently logic to handle napi tx completion is flawed and on the long
+run on loaded condition cause TX timeout error with the queue not being
+able to handle any new packet.
+
+There are 2 main cause of this:
+- incrementing the packet done value wrongly
+- handling 2 times the tx_ring tail
+
+ipqess_tx_unmap_and_free may return 2 kind values:
+- 0: we are handling first and middle descriptor for the packet
+- packet len: we are at the last descriptor for the packet
+
+Done value was wrongly incremented also for first and intermediate
+descriptor for the packet resulting causing panic and TX timeouts by
+comunicating to the kernel an inconsistent value of packet handling not
+matching the expected ones.
+
+Tx_ring tail was handled twice for ipqess_tx_complete run resulting in
+again done value incremented wrongly and also problem with idx handling
+by actually skipping descriptor for some packets.
+
+Rework the loop logic to fix these 2 problem and also add some comments
+to make sure ipqess_tx_unmap_and_free ret value is better
+understandable.
+
+Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
+---
+ drivers/net/ethernet/qualcomm/ipqess/ipqess.c | 13 ++++++++++---
+ 1 file changed, 10 insertions(+), 3 deletions(-)
+
+--- a/drivers/net/ethernet/qualcomm/ipqess/ipqess.c
++++ b/drivers/net/ethernet/qualcomm/ipqess/ipqess.c
+@@ -453,13 +453,22 @@ static int ipqess_tx_complete(struct ipq
+ 	tail >>= IPQESS_TPD_CONS_IDX_SHIFT;
+ 	tail &= IPQESS_TPD_CONS_IDX_MASK;
+ 
+-	do {
++	while ((tx_ring->tail != tail) && (done < budget)) {
+ 		ret = ipqess_tx_unmap_and_free(&tx_ring->ess->pdev->dev,
+ 					       &tx_ring->buf[tx_ring->tail]);
+-		tx_ring->tail = IPQESS_NEXT_IDX(tx_ring->tail, tx_ring->count);
++		/* ipqess_tx_unmap_and_free may return 2 kind values:
++		 * - 0: we are handling first and middle descriptor for the packet
++		 * - packet len: we are at the last descriptor for the packet
++		 * Increment total bytes handled and packet done only if we are
++		 * handling the last descriptor for the packet.
++		 */
++		if (ret) {
++			total += ret;
++			done++;
++		}
+ 
+-		total += ret;
+-	} while ((++done < budget) && (tx_ring->tail != tail));
++		tx_ring->tail = IPQESS_NEXT_IDX(tx_ring->tail, tx_ring->count);
++	};
+ 
+ 	ipqess_w32(tx_ring->ess, IPQESS_REG_TX_SW_CONS_IDX_Q(tx_ring->idx),
+ 		   tx_ring->tail);