[ 14/49] sfc: lock TX queues when calling netif_device_detach()

Greg Kroah-Hartman
2013-03-26T23:14:43Z

From: Daniel Pieczko <dpieczko@solarflare.com>

[ Upstream commit c2f3b8e3a44b6fe9e36704e30157ebe1a88c08b1 ]

The assertion of netif_device_present() at the top of
efx_hard_start_xmit() may fail if we don't do this.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
[bwh: Backported to 3.0: adjust context]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/sfc/efx.c | 4 ++--
drivers/net/sfc/efx.h | 13 +++++++++++++
drivers/net/sfc/selftest.c | 2 +-
3 files changed, 16 insertions(+), 3 deletions(-)

--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -2106,7 +2106,7 @@ int efx_reset(struct efx_nic *efx, enum
netif_info(efx, drv, efx->net_dev, "resetting (%s)\n",
RESET_TYPE(method));

- netif_device_detach(efx->net_dev);
+ efx_device_detach_sync(efx);
efx_reset_down(efx, method);

rc = efx->type->reset(efx, method);
@@ -2565,7 +2565,7 @@ static int efx_pm_freeze(struct device *

efx->state = STATE_FINI;

- netif_device_detach(efx->net_dev);
+ efx_device_detach_sync(efx);

efx_stop_all(efx);
efx_fini_channels(efx);
--- a/drivers/net/sfc/efx.h
+++ b/drivers/net/sfc/efx.h
@@ -150,4 +150,17 @@ extern void efx_link_status_changed(stru
extern void efx_link_set_advertising(struct efx_nic *efx, u32);
extern void efx_link_set_wanted_fc(struct efx_nic *efx, u8);

+static inline void efx_device_detach_sync(struct efx_nic *efx)
+{
+ struct net_device *dev = efx->net_dev;
+
+ /* Lock/freeze all TX queues so that we can be sure the
+ * TX scheduler is stopped when we're done and before
+ * netif_device_present() becomes false.
+ */
+ netif_tx_lock(dev);
+ netif_device_detach(dev);
+ netif_tx_unlock(dev);
+}
+
#endif /* EFX_EFX_H */
--- a/drivers/net/sfc/selftest.c
+++ b/drivers/net/sfc/selftest.c
@@ -698,7 +698,7 @@ int efx_selftest(struct efx_nic *efx, st
/* Detach the device so the kernel doesn't transmit during the
* loopback test and the watchdog timeout doesn't fire.
*/
- netif_device_detach(efx->net_dev);
+ efx_device_detach_sync(efx);

mutex_lock(&efx->mac_lock);
if (efx->loopback_modes) {