From: Bryan Whitehead <Bryan.Whitehead@microchip.com>
To: <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>, <UNGLinuxDriver@microchip.com>
Subject: [PATCH v1 net] lan743x: Fix TX Stall Issue
Date: Tue, 26 Feb 2019 14:06:26 -0500 [thread overview]
Message-ID: <1551207986-7283-1-git-send-email-Bryan.Whitehead@microchip.com> (raw)
It has been observed that tx queue stalls while downloading
from certain web sites (example www.speedtest.net)
The cause has been tracked down to a corner case where
dma descriptors where not setup properly. And there for a tx
completion interrupt was not signaled.
This fix corrects the problem by properly marking the end of
a multi descriptor transmission.
fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Bryan Whitehead <Bryan.Whitehead@microchip.com>
---
drivers/net/ethernet/microchip/lan743x_main.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 310807e..4d1b4a2 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1400,7 +1400,8 @@ static int lan743x_tx_frame_start(struct lan743x_tx *tx,
}
static void lan743x_tx_frame_add_lso(struct lan743x_tx *tx,
- unsigned int frame_length)
+ unsigned int frame_length,
+ int nr_frags)
{
/* called only from within lan743x_tx_xmit_frame.
* assuming tx->ring_lock has already been acquired.
@@ -1410,6 +1411,10 @@ static void lan743x_tx_frame_add_lso(struct lan743x_tx *tx,
/* wrap up previous descriptor */
tx->frame_data0 |= TX_DESC_DATA0_EXT_;
+ if (nr_frags <= 0) {
+ tx->frame_data0 |= TX_DESC_DATA0_LS_;
+ tx->frame_data0 |= TX_DESC_DATA0_IOC_;
+ }
tx_descriptor = &tx->ring_cpu_ptr[tx->frame_tail];
tx_descriptor->data0 = tx->frame_data0;
@@ -1514,8 +1519,11 @@ static void lan743x_tx_frame_end(struct lan743x_tx *tx,
u32 tx_tail_flags = 0;
/* wrap up previous descriptor */
- tx->frame_data0 |= TX_DESC_DATA0_LS_;
- tx->frame_data0 |= TX_DESC_DATA0_IOC_;
+ if ((tx->frame_data0 & TX_DESC_DATA0_DTYPE_MASK_) ==
+ TX_DESC_DATA0_DTYPE_DATA_) {
+ tx->frame_data0 |= TX_DESC_DATA0_LS_;
+ tx->frame_data0 |= TX_DESC_DATA0_IOC_;
+ }
tx_descriptor = &tx->ring_cpu_ptr[tx->frame_tail];
buffer_info = &tx->buffer_info[tx->frame_tail];
@@ -1600,7 +1608,7 @@ static netdev_tx_t lan743x_tx_xmit_frame(struct lan743x_tx *tx,
}
if (gso)
- lan743x_tx_frame_add_lso(tx, frame_length);
+ lan743x_tx_frame_add_lso(tx, frame_length, nr_frags);
if (nr_frags <= 0)
goto finish;
--
2.7.4
next reply other threads:[~2019-02-26 19:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-26 19:06 Bryan Whitehead [this message]
2019-03-01 19:34 ` [PATCH v1 net] lan743x: Fix TX Stall Issue David Miller
2019-03-13 19:55 Bryan Whitehead
2019-03-13 20:43 ` David Miller
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