Commit 90490ef7 authored by Bryan Whitehead's avatar Bryan Whitehead Committed by David S. Miller

lan743x: Fix TX Stall Issue

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: 23f0703c ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: default avatarBryan Whitehead <Bryan.Whitehead@microchip.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d25ed413
...@@ -1400,7 +1400,8 @@ static int lan743x_tx_frame_start(struct lan743x_tx *tx, ...@@ -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, 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. /* called only from within lan743x_tx_xmit_frame.
* assuming tx->ring_lock has already been acquired. * assuming tx->ring_lock has already been acquired.
...@@ -1410,6 +1411,10 @@ static void lan743x_tx_frame_add_lso(struct lan743x_tx *tx, ...@@ -1410,6 +1411,10 @@ static void lan743x_tx_frame_add_lso(struct lan743x_tx *tx,
/* wrap up previous descriptor */ /* wrap up previous descriptor */
tx->frame_data0 |= TX_DESC_DATA0_EXT_; 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 = &tx->ring_cpu_ptr[tx->frame_tail];
tx_descriptor->data0 = tx->frame_data0; tx_descriptor->data0 = tx->frame_data0;
...@@ -1514,8 +1519,11 @@ static void lan743x_tx_frame_end(struct lan743x_tx *tx, ...@@ -1514,8 +1519,11 @@ static void lan743x_tx_frame_end(struct lan743x_tx *tx,
u32 tx_tail_flags = 0; u32 tx_tail_flags = 0;
/* wrap up previous descriptor */ /* wrap up previous descriptor */
tx->frame_data0 |= TX_DESC_DATA0_LS_; if ((tx->frame_data0 & TX_DESC_DATA0_DTYPE_MASK_) ==
tx->frame_data0 |= TX_DESC_DATA0_IOC_; 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]; tx_descriptor = &tx->ring_cpu_ptr[tx->frame_tail];
buffer_info = &tx->buffer_info[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, ...@@ -1600,7 +1608,7 @@ static netdev_tx_t lan743x_tx_xmit_frame(struct lan743x_tx *tx,
} }
if (gso) if (gso)
lan743x_tx_frame_add_lso(tx, frame_length); lan743x_tx_frame_add_lso(tx, frame_length, nr_frags);
if (nr_frags <= 0) if (nr_frags <= 0)
goto finish; goto finish;
......
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