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authorDave Jiang <dave.jiang@intel.com>2023-08-22 19:04:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-09-13 10:43:02 +0300
commit5a3e327dc3fdf9586d3ed00f82e41b54f2c1e2af (patch)
tree964467b0ffa2fa31d0e82581eb856a56daebe28d /drivers/ntb
parent88c7931f81d859713473bcdf99bf92b090ddab4d (diff)
downloadlinux-5a3e327dc3fdf9586d3ed00f82e41b54f2c1e2af.tar.xz
ntb: Fix calculation ntb_transport_tx_free_entry()
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@deltatee.com> Signed-off-by: renlonglong <ren.longlong@h3c.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/ntb')
-rw-r--r--drivers/ntb/ntb_transport.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 7884ea9c7643..9532108d2dce 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -2429,7 +2429,7 @@ unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
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);