[ 11/49] sfc: Do not attempt to flush queues if DMA is disabled

Greg Kroah-Hartman
2013-03-26T23:15:50Z

From: Stuart Hodgson <smhodgson@solarflare.com>

[ Upstream commit 3dca9d2dc285faf1910d405b65df845cab061356 ]

efx_nic_fatal_interrupt() disables DMA before scheduling a reset.
After this, we need not and *cannot* flush queues.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/sfc/efx.c | 33 +++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)

--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -651,25 +651,30 @@ static void efx_fini_channels(struct efx
struct efx_channel *channel;
struct efx_tx_queue *tx_queue;
struct efx_rx_queue *rx_queue;
+ struct pci_dev *dev = efx->pci_dev;
int rc;

EFX_ASSERT_RESET_SERIALISED(efx);
BUG_ON(efx->port_enabled);

- rc = efx_nic_flush_queues(efx);
- if (rc && EFX_WORKAROUND_7803(efx)) {
- /* Schedule a reset to recover from the flush failure. The
- * descriptor caches reference memory we're about to free,
- * but falcon_reconfigure_mac_wrapper() won't reconnect
- * the MACs because of the pending reset. */
- netif_err(efx, drv, efx->net_dev,
- "Resetting to recover from flush failure\n");
- efx_schedule_reset(efx, RESET_TYPE_ALL);
- } else if (rc) {
- netif_err(efx, drv, efx->net_dev, "failed to flush queues\n");
- } else {
- netif_dbg(efx, drv, efx->net_dev,
- "successfully flushed all queues\n");
+ /* Only perform flush if dma is enabled */
+ if (dev->is_busmaster) {
+ rc = efx_nic_flush_queues(efx);
+
+ if (rc && EFX_WORKAROUND_7803(efx)) {
+ /* Schedule a reset to recover from the flush failure. The
+ * descriptor caches reference memory we're about to free,
+ * but falcon_reconfigure_mac_wrapper() won't reconnect
+ * the MACs because of the pending reset. */
+ netif_err(efx, drv, efx->net_dev,
+ "Resetting to recover from flush failure\n");
+ efx_schedule_reset(efx, RESET_TYPE_ALL);
+ } else if (rc) {
+ netif_err(efx, drv, efx->net_dev, "failed to flush queues\n");
+ } else {
+ netif_dbg(efx, drv, efx->net_dev,
+ "successfully flushed all queues\n");
+ }
}

efx_for_each_channel(channel, efx) {