Commit 8b7325b4 authored by Ben Hutchings's avatar Ben Hutchings
Browse files

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: default avatarBen Hutchings <bhutchings@solarflare.com>
parent 5642ceef

drivers/net/ethernet/sfc/efx.c

+44 −21
Original line number Diff line number Diff line
@@ -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);

	}



	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;

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