From: Ben Hutchings Date: Fri, 27 Jul 2012 19:46:41 +0000 (+0100) Subject: sfc: Never try to stop and start a NIC that is disabled X-Git-Tag: MMI-PSA29.97-13-9~15870^2~277^2~6 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8b7325b4e29256881117aff8a162e829c79b47e9;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git sfc: Never try to stop and start a NIC that is disabled efx_change_mtu() and efx_realloc_channels() each stop and start much of the NIC, even if it has been disabled. Since efx_start_all() is a no-op when the NIC is disabled, this is probably harmless in the case of efx_change_mtu(), but efx_realloc_channels() also reenables interrupts which could be a bad thing to do. Change efx_start_all() and efx_start_interrupts() to assert that the NIC is not disabled, but make efx_stop_interrupts() do nothing if the NIC is disabled (since it is already stopped), consistent with efx_stop_all(). Update comments for efx_start_all() and efx_stop_all() to describe their purpose and preconditions more accurately. Add a common function to check and log if the NIC is disabled, and use it in efx_net_open(), efx_change_mtu() and efx_realloc_channels(). Signed-off-by: Ben Hutchings --- diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index 629029e2037d..977fc3a591e9 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -207,6 +207,16 @@ static void efx_stop_all(struct efx_nic *efx); ASSERT_RTNL(); \ } while (0) +static int efx_check_disabled(struct efx_nic *efx) +{ + if (efx->state == STATE_DISABLED) { + netif_err(efx, drv, efx->net_dev, + "device is disabled due to earlier errors\n"); + return -EIO; + } + return 0; +} + /************************************************************************** * * Event queue processing @@ -740,7 +750,11 @@ efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries) struct efx_channel *other_channel[EFX_MAX_CHANNELS], *channel; u32 old_rxq_entries, old_txq_entries; unsigned i, next_buffer_table = 0; - int rc = 0; + int rc; + + rc = efx_check_disabled(efx); + if (rc) + return rc; /* Not all channels should be reallocated. We must avoid * reallocating their buffer table entries. @@ -1375,6 +1389,8 @@ static void efx_start_interrupts(struct efx_nic *efx, bool may_keep_eventq) { struct efx_channel *channel; + BUG_ON(efx->state == STATE_DISABLED); + if (efx->legacy_irq) efx->legacy_irq_enabled = true; efx_nic_enable_interrupts(efx); @@ -1392,6 +1408,9 @@ static void efx_stop_interrupts(struct efx_nic *efx, bool may_keep_eventq) { struct efx_channel *channel; + if (efx->state == STATE_DISABLED) + return; + efx_mcdi_mode_poll(efx); efx_nic_disable_interrupts(efx); @@ -1543,22 +1562,21 @@ static int efx_probe_all(struct efx_nic *efx) return rc; } -/* Called after previous invocation(s) of efx_stop_all, restarts the port, - * kernel transmit queues and NAPI processing, and ensures that the port is - * scheduled to be reconfigured. This function is safe to call multiple - * times when the NIC is in any state. +/* If the interface is supposed to be running but is not, start + * the hardware and software data path, regular activity for the port + * (MAC statistics, link polling, etc.) and schedule the port to be + * reconfigured. Interrupts must already be enabled. This function + * is safe to call multiple times, so long as the NIC is not disabled. + * Requires the RTNL lock. */ static void efx_start_all(struct efx_nic *efx) { EFX_ASSERT_RESET_SERIALISED(efx); + BUG_ON(efx->state == STATE_DISABLED); /* Check that it is appropriate to restart the interface. All * of these flags are safe to read under just the rtnl lock */ - if (efx->port_enabled) - return; - if ((efx->state != STATE_READY) && (efx->state != STATE_UNINIT)) - return; - if (!netif_running(efx->net_dev)) + if (efx->port_enabled || !netif_running(efx->net_dev)) return; efx_start_port(efx); @@ -1592,11 +1610,11 @@ static void efx_flush_all(struct efx_nic *efx) cancel_work_sync(&efx->mac_work); } -/* Quiesce hardware and software without bringing the link down. - * Safe to call multiple times, when the nic and interface is in any - * state. The caller is guaranteed to subsequently be in a position - * to modify any hardware and software state they see fit without - * taking locks. */ +/* Quiesce the hardware and software data path, and regular activity + * for the port without bringing the link down. Safe to call multiple + * times with the NIC in almost any state, but interrupts should be + * enabled. Requires the RTNL lock. + */ static void efx_stop_all(struct efx_nic *efx) { EFX_ASSERT_RESET_SERIALISED(efx); @@ -1830,13 +1848,16 @@ static void efx_netpoll(struct net_device *net_dev) static int efx_net_open(struct net_device *net_dev) { struct efx_nic *efx = netdev_priv(net_dev); + int rc; + EFX_ASSERT_RESET_SERIALISED(efx); netif_dbg(efx, ifup, efx->net_dev, "opening device on CPU %d\n", raw_smp_processor_id()); - if (efx->state == STATE_DISABLED) - return -EIO; + rc = efx_check_disabled(efx); + if (rc) + return rc; if (efx->phy_mode & PHY_MODE_SPECIAL) return -EBUSY; if (efx_mcdi_poll_reboot(efx) && efx_reset(efx, RESET_TYPE_ALL)) @@ -1862,10 +1883,8 @@ static int efx_net_stop(struct net_device *net_dev) netif_dbg(efx, ifdown, efx->net_dev, "closing on CPU %d\n", raw_smp_processor_id()); - if (efx->state != STATE_DISABLED) { - /* Stop the device and flush all the channels */ - efx_stop_all(efx); - } + /* Stop the device and flush all the channels */ + efx_stop_all(efx); return 0; } @@ -1925,9 +1944,13 @@ static void efx_watchdog(struct net_device *net_dev) static int efx_change_mtu(struct net_device *net_dev, int new_mtu) { struct efx_nic *efx = netdev_priv(net_dev); + int rc; EFX_ASSERT_RESET_SERIALISED(efx); + rc = efx_check_disabled(efx); + if (rc) + return rc; if (new_mtu > EFX_MAX_MTU) return -EINVAL;