From 80cca775cdc4f8555612d2943a2872076b33e0ff Mon Sep 17 00:00:00 2001 From: Nikita Yushchenko Date: Tue, 29 Nov 2016 09:44:51 +0300 Subject: [PATCH] net: fec: cache statistics while device is down Execution 'ethtool -S' on fec device that is down causes OOPS on Vybrid board: Unhandled fault: external abort on non-linefetch (0x1008) at 0xe0898200 pgd = ddecc000 [e0898200] *pgd=9e406811, *pte=400d1653, *ppte=400d1453 Internal error: : 1008 [#1] SMP ARM ... Reason of OOPS is that fec_enet_get_ethtool_stats() accesses fec registers while IPG clock is stopped by PM. Fix that by caching statistics in fec_enet_private. Cache is initialized at device probe time, and updated at statistics request time if device is up, and also just before turning device off on down path. Additional locking is not needed, since cached statistics is accessed either before device is registered, or under rtnl_lock(). Signed-off-by: Nikita Yushchenko Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec.h | 2 ++ drivers/net/ethernet/freescale/fec_main.c | 23 +++++++++++++++++++---- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h index c865135f3cb91..5ea740b4cf14c 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -574,6 +574,8 @@ struct fec_enet_private { unsigned int reload_period; int pps_enable; unsigned int next_counter; + + u64 ethtool_stats[0]; }; void fec_ptp_init(struct platform_device *pdev); diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 74dcdf0973487..5f77caa59534d 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -2313,14 +2313,24 @@ static const struct fec_stat { { "IEEE_rx_octets_ok", IEEE_R_OCTETS_OK }, }; -static void fec_enet_get_ethtool_stats(struct net_device *dev, - struct ethtool_stats *stats, u64 *data) +static void fec_enet_update_ethtool_stats(struct net_device *dev) { struct fec_enet_private *fep = netdev_priv(dev); int i; for (i = 0; i < ARRAY_SIZE(fec_stats); i++) - data[i] = readl(fep->hwp + fec_stats[i].offset); + fep->ethtool_stats[i] = readl(fep->hwp + fec_stats[i].offset); +} + +static void fec_enet_get_ethtool_stats(struct net_device *dev, + struct ethtool_stats *stats, u64 *data) +{ + struct fec_enet_private *fep = netdev_priv(dev); + + if (netif_running(dev)) + fec_enet_update_ethtool_stats(dev); + + memcpy(data, fep->ethtool_stats, ARRAY_SIZE(fec_stats) * sizeof(u64)); } static void fec_enet_get_strings(struct net_device *netdev, @@ -2874,6 +2884,8 @@ fec_enet_close(struct net_device *ndev) if (fep->quirks & FEC_QUIRK_ERR006687) imx6q_cpuidle_fec_irqs_unused(); + fec_enet_update_ethtool_stats(ndev); + fec_enet_clk_enable(ndev, false); pinctrl_pm_select_sleep_state(&fep->pdev->dev); pm_runtime_mark_last_busy(&fep->pdev->dev); @@ -3180,6 +3192,8 @@ static int fec_enet_init(struct net_device *ndev) fec_restart(ndev); + fec_enet_update_ethtool_stats(ndev); + return 0; } @@ -3278,7 +3292,8 @@ fec_probe(struct platform_device *pdev) fec_enet_get_queue_num(pdev, &num_tx_qs, &num_rx_qs); /* Init network device */ - ndev = alloc_etherdev_mqs(sizeof(struct fec_enet_private), + ndev = alloc_etherdev_mqs(sizeof(struct fec_enet_private) + + ARRAY_SIZE(fec_stats) * sizeof(u64), num_tx_qs, num_rx_qs); if (!ndev) return -ENOMEM;