From: Niklas Cassel <niklas.cas...@axis.com>
The dwmac4 IP can synthesized with 1-8 number of tx queues.
On an IP synthesized with DWC_EQOS_NUM_TXQ > 1, all txqueues are disabled
by default. For these IPs, the bitfield TXQEN is R/W.
Always enable tx queue 0. The write will have no effect on IPs synthesized
with DWC_EQOS_NUM_TXQ == 1.
The driver does still not utilize more than one tx queue in the IP.
Signed-off-by: Niklas Cassel <niklas.cas...@axis.com>
---
drivers/net/ethernet/stmicro/stmmac/dwmac4.h | 3 +++
drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 12 +++++++++++-
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index 6f4f5ce25114..3e8d4fefa5e0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -155,8 +155,11 @@ enum power_event {
#define MTL_CHAN_RX_DEBUG(x) (MTL_CHANX_BASE_ADDR(x) + 0x38)
#define MTL_OP_MODE_RSF BIT(5)
+#define MTL_OP_MODE_TXQEN BIT(3)
#define MTL_OP_MODE_TSF BIT(1)
+#define MTL_OP_MODE_TQS_MASK GENMASK(24, 16)
+
#define MTL_OP_MODE_TTC_MASK 0x70
#define MTL_OP_MODE_TTC_SHIFT 4
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 116151cd6a95..577316de6ba8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -213,7 +213,17 @@ static void dwmac4_dma_chan_op_mode(void __iomem *ioaddr,
int txmode,
else
mtl_tx_op |= MTL_OP_MODE_TTC_512;
}
-
+ /* For an IP with DWC_EQOS_NUM_TXQ == 1, the fields TXQEN and TQS are RO
+ * with reset values: TXQEN on, TQS == DWC_EQOS_TXFIFO_SIZE.
+ * For an IP with DWC_EQOS_NUM_TXQ > 1, the fields TXQEN and TQS are R/W
+ * with reset values: TXQEN off, TQS 256 bytes.
+ *
+ * Write the bits in both cases, since it will have no effect when RO.
+ * For DWC_EQOS_NUM_TXQ > 1, the top bits in MTL_OP_MODE_TQS_MASK might
+ * be RO, however, writing the whole TQS field will result in a value
+ * equal to DWC_EQOS_TXFIFO_SIZE, just like for DWC_EQOS_NUM_TXQ == 1.
+ */
+ mtl_tx_op |= MTL_OP_MODE_TXQEN | MTL_OP_MODE_TQS_MASK;
writel(mtl_tx_op, ioaddr + MTL_CHAN_TX_OP_MODE(channel));
mtl_rx_op = readl(ioaddr + MTL_CHAN_RX_OP_MODE(channel));
--
2.1.4
