This is a note to let you know that I've just added the patch titled
ntb: Fix calculation ntb_transport_tx_free_entry()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ntb-fix-calculation-ntb_transport_tx_free_entry.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5a7693e6bbf19b22fd6c1d2c4b7beb0a03969e2c Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@xxxxxxxxx>
Date: Tue, 22 Aug 2023 09:04:57 -0700
Subject: ntb: Fix calculation ntb_transport_tx_free_entry()
From: Dave Jiang <dave.jiang@xxxxxxxxx>
commit 5a7693e6bbf19b22fd6c1d2c4b7beb0a03969e2c upstream.
ntb_transport_tx_free_entry() never returns 0 with the current
calculation. If head == tail, then it would return qp->tx_max_entry.
Change compare to tail >= head and when they are equal, a 0 would be
returned.
Fixes: e74bfeedad08 ("NTB: Add flow control to the ntb_netdev")
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: renlonglong <ren.longlong@xxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Signed-off-by: Jon Mason <jdmason@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/ntb/ntb_transport.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -2199,7 +2199,7 @@ unsigned int ntb_transport_tx_free_entry
unsigned int head = qp->tx_index;
unsigned int tail = qp->remote_rx_info->entry;
- return tail > head ? tail - head : qp->tx_max_entry + tail - head;
+ return tail >= head ? tail - head : qp->tx_max_entry + tail - head;
}
EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
Patches currently in stable-queue which might be from dave.jiang@xxxxxxxxx are
queue-4.19/ntb-fix-calculation-ntb_transport_tx_free_entry.patch
queue-4.19/ntb-clean-up-tx-tail-index-on-link-down.patch
queue-4.19/ntb-drop-packets-when-qp-link-is-down.patch
