From 90490ef7269906423a1c1b917fc24be8b1602658 Mon Sep 17 00:00:00 2001 From: Bryan Whitehead Date: Tue, 26 Feb 2019 14:06:26 -0500 Subject: [PATCH] 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: 23f0703c125b ("lan743x: Add main source files for new lan743x driver") Signed-off-by: Bryan Whitehead Signed-off-by: David S. Miller --- 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 310807ef328b..4d1b4a24907f 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; -- 2.11.0