2017-11-14 11:28:56

by Niklas Cassel

[permalink] [raw]
Subject: [PATCH net-next v2] net: stmmac: fix LPI transitioning for dwmac4

The LPI transitioning logic in stmmac_main uses
priv->tx_path_in_lpi_mode to enter/exit LPI.

However, priv->tx_path_in_lpi_mode is assigned
using the return value from host_irq_status().

So for dwmac4, priv->tx_path_in_lpi_mode was always false,
so stmmac_tx_clean() would always try to put us in eee mode,
and stmmac_xmit() would never take us out of eee mode.

To fix this, make host_irq_status() read and return the LPI
irq status also for dwmac4.

This also increments the existing LPI counters, so that
ethtool --statistics shows LPI transitions also for dwmac4.

For dwmac1000, irqs are enabled/disabled using the register
named "Interrupt Mask Register", and thus setting a bit disables
that specific irq.

For dwmac4 the matching register is named "MAC_Interrupt_Enable",
and thus setting a bit enables that specific irq.

Looking at dwmac1000_core.c, the irqs that are always enabled are:
LPI and PMT.

Looking at dwmac4_core.c, the irqs that are always enabled are:
PMT.

To be able to read the LPI irq status, we need to enable the LPI
irq also for dwmac4.

Signed-off-by: Niklas Cassel <[email protected]>
---
Changes since v1:
Fixed two typos in the commit message.

drivers/net/ethernet/stmicro/stmmac/dwmac4.h | 7 ++++++-
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 19 +++++++++++++++++++
2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index aeda3ab2d761..789dad8a07b5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -98,7 +98,7 @@
#define GMAC_PCS_IRQ_DEFAULT (GMAC_INT_RGSMIIS | GMAC_INT_PCS_LINK | \
GMAC_INT_PCS_ANE)

-#define GMAC_INT_DEFAULT_MASK GMAC_INT_PMT_EN
+#define GMAC_INT_DEFAULT_MASK (GMAC_INT_PMT_EN | GMAC_INT_LPI_EN)

enum dwmac4_irq_status {
time_stamp_irq = 0x00001000,
@@ -106,6 +106,7 @@ enum dwmac4_irq_status {
mmc_tx_irq = 0x00000400,
mmc_rx_irq = 0x00000200,
mmc_irq = 0x00000100,
+ lpi_irq = 0x00000020,
pmt_irq = 0x00000010,
};

@@ -132,6 +133,10 @@ enum power_event {
#define GMAC4_LPI_CTRL_STATUS_LPITXA BIT(19) /* Enable LPI TX Automate */
#define GMAC4_LPI_CTRL_STATUS_PLS BIT(17) /* PHY Link Status */
#define GMAC4_LPI_CTRL_STATUS_LPIEN BIT(16) /* LPI Enable */
+#define GMAC4_LPI_CTRL_STATUS_RLPIEX BIT(3) /* Receive LPI Exit */
+#define GMAC4_LPI_CTRL_STATUS_RLPIEN BIT(2) /* Receive LPI Entry */
+#define GMAC4_LPI_CTRL_STATUS_TLPIEX BIT(1) /* Transmit LPI Exit */
+#define GMAC4_LPI_CTRL_STATUS_TLPIEN BIT(0) /* Transmit LPI Entry */

/* MAC Debug bitmap */
#define GMAC_DEBUG_TFCSTS_MASK GENMASK(18, 17)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index 2f7d7ec59962..f3ed8f7853eb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -580,6 +580,25 @@ static int dwmac4_irq_status(struct mac_device_info *hw,
x->irq_receive_pmt_irq_n++;
}

+ /* MAC tx/rx EEE LPI entry/exit interrupts */
+ if (intr_status & lpi_irq) {
+ /* Clear LPI interrupt by reading MAC_LPI_Control_Status */
+ u32 status = readl(ioaddr + GMAC4_LPI_CTRL_STATUS);
+
+ if (status & GMAC4_LPI_CTRL_STATUS_TLPIEN) {
+ ret |= CORE_IRQ_TX_PATH_IN_LPI_MODE;
+ x->irq_tx_path_in_lpi_mode_n++;
+ }
+ if (status & GMAC4_LPI_CTRL_STATUS_TLPIEX) {
+ ret |= CORE_IRQ_TX_PATH_EXIT_LPI_MODE;
+ x->irq_tx_path_exit_lpi_mode_n++;
+ }
+ if (status & GMAC4_LPI_CTRL_STATUS_RLPIEN)
+ x->irq_rx_path_in_lpi_mode_n++;
+ if (status & GMAC4_LPI_CTRL_STATUS_RLPIEX)
+ x->irq_rx_path_exit_lpi_mode_n++;
+ }
+
dwmac_pcs_isr(ioaddr, GMAC_PCS_BASE, intr_status, x);
if (intr_status & PCS_RGSMIIIS_IRQ)
dwmac4_phystatus(ioaddr, x);
--
2.14.2


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