net/faraday: Mask out PHYSTS_CHG interrupt

The PHYSTS_CHG (the ftgmac100's PHY IRQ) is telling the system to go
look at the PHY registers for a link status change.

The interrupt was causing issues on Aspeed SoC where some board designs
had an active high configuration, some active low, and in some cases
repurposed for other functions. When misconfigured Linux would chew 100%
of CPU cycles servicing interrupts:

 [   20.280000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG
 [   20.280000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG
 [   20.280000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG
 [   20.300000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG

While in the ftgmac100 IP can be configured for high, low and edge
sensitivity the current driver always polls the PHY, so we chose to mask
out the interrupt.

See https://patchwork.ozlabs.org/patch/672099/ for more discussion.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index e3653b14008a4f8e0d0653764e3384ea9d2689ef..90f9c5481290e0d3cbf797f9d31f8b3edcc6b519 100644 (file)
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1075,14 +1075,12 @@ static int ftgmac100_poll(struct napi_struct *napi, int budget)
        }
 
        if (status & priv->int_mask_all & (FTGMAC100_INT_NO_RXBUF |
-                       FTGMAC100_INT_RPKT_LOST | FTGMAC100_INT_AHB_ERR |
-                       FTGMAC100_INT_PHYSTS_CHG)) {
+                       FTGMAC100_INT_RPKT_LOST | FTGMAC100_INT_AHB_ERR)) {
                if (net_ratelimit())
-                       netdev_info(netdev, "[ISR] = 0x%x: %s%s%s%s\n", status,
+                       netdev_info(netdev, "[ISR] = 0x%x: %s%s%s\n", status,
                                    status & FTGMAC100_INT_NO_RXBUF ? "NO_RXBUF " : "",
                                    status & FTGMAC100_INT_RPKT_LOST ? "RPKT_LOST " : "",
-                                   status & FTGMAC100_INT_AHB_ERR ? "AHB_ERR " : "",
-                                   status & FTGMAC100_INT_PHYSTS_CHG ? "PHYSTS_CHG" : "");
+                                   status & FTGMAC100_INT_AHB_ERR ? "AHB_ERR " : "");
 
                if (status & FTGMAC100_INT_NO_RXBUF) {
                        /* RX buffer unavailable */
@@ -1390,7 +1388,6 @@ static int ftgmac100_probe(struct platform_device *pdev)
                              FTGMAC100_INT_XPKT_ETH |
                              FTGMAC100_INT_XPKT_LOST |
                              FTGMAC100_INT_AHB_ERR |
-                             FTGMAC100_INT_PHYSTS_CHG |
                              FTGMAC100_INT_RPKT_BUF |
                              FTGMAC100_INT_NO_RXBUF);
 
@@ -1412,7 +1409,6 @@ static int ftgmac100_probe(struct platform_device *pdev)
 
                dev_info(&pdev->dev, "Using NCSI interface\n");
                priv->use_ncsi = true;
-               priv->int_mask_all &= ~FTGMAC100_INT_PHYSTS_CHG;
                priv->ndev = ncsi_register_dev(netdev, ftgmac100_ncsi_handler);
                if (!priv->ndev)
                        goto err_ncsi_dev;

diff --git a/drivers/net/ethernet/faraday/ftgmac100.h b/drivers/net/ethernet/faraday/ftgmac100.h
index 8a377ab1d127bf732a42dc2420f5a51147e5da67..a7ce0ac8858a5f1a123be8ca46a03bc5fa18f9f0 100644 (file)
--- a/drivers/net/ethernet/faraday/ftgmac100.h
+++ b/drivers/net/ethernet/faraday/ftgmac100.h
@@ -157,6 +157,7 @@
 #define FTGMAC100_MACCR_FULLDUP                (1 << 8)
 #define FTGMAC100_MACCR_GIGA_MODE      (1 << 9)
 #define FTGMAC100_MACCR_CRC_APD                (1 << 10)
+#define FTGMAC100_MACCR_PHY_LINK_LEVEL (1 << 11)
 #define FTGMAC100_MACCR_RX_RUNT                (1 << 12)
 #define FTGMAC100_MACCR_JUMBO_LF       (1 << 13)
 #define FTGMAC100_MACCR_RX_ALL         (1 << 14)