Merge tag 'v3.15-rc6' into patchwork

Linux 3.15-rc6

* tag 'v3.15-rc6': (1314 commits)
  Linux 3.15-rc6
  Btrfs: send, fix incorrect ref access when using extrefs
  Btrfs: fix EIO on reading file after ioctl clone works on it
  scripts/checksyscalls.sh: Make renameat optional
  asm-generic: Add renameat2 syscall
  ia64: add renameat2 syscall
  parisc: add renameat2 syscall
  m68k: add renameat2 syscall
  sysfs: make sure read buffer is zeroed
  ahci: imx: PLL clock needs 100us to settle down
  PCI: Wrong register used to check pending traffic
  target: fix memory leak on XCOPY
  random: fix BUG_ON caused by accounting simplification
  clk: tegra: Fix wrong value written to PLLE_AUX
  staging: rtl8723au: Do not reset wdev->iftype in netdev_close()
  ACPI / video: Revert native brightness quirk for ThinkPad T530
  staging: rtl8723au: Use correct pipe type for USB interrupts
  crush: decode and initialize chooseleaf_vary_r
  libceph: fix corruption when using page_count 0 page in rbd
  arm64: fix pud_huge() for 2-level pagetables
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index a08761360cdf..0537381cd2f6 100644
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -741,6 +741,28 @@ int efx_farch_fini_dmaq(struct efx_nic *efx)
 	return rc;
 }
 
+/* Reset queue and flush accounting after FLR
+ *
+ * One possible cause of FLR recovery is that DMA may be failing (eg. if bus
+ * mastering was disabled), in which case we don't receive (RXQ) flush
+ * completion events.  This means that efx->rxq_flush_outstanding remained at 4
+ * after the FLR; also, efx->active_queues was non-zero (as no flush completion
+ * events were received, and we didn't go through efx_check_tx_flush_complete())
+ * If we don't fix this up, on the next call to efx_realloc_channels() we won't
+ * flush any RX queues because efx->rxq_flush_outstanding is at the limit of 4
+ * for batched flush requests; and the efx->active_queues gets messed up because
+ * we keep incrementing for the newly initialised queues, but it never went to
+ * zero previously.  Then we get a timeout every time we try to restart the
+ * queues, as it doesn't go back to zero when we should be flushing the queues.
+ */
+void efx_farch_finish_flr(struct efx_nic *efx)
+{
+	atomic_set(&efx->rxq_flush_pending, 0);
+	atomic_set(&efx->rxq_flush_outstanding, 0);
+	atomic_set(&efx->active_queues, 0);
+}
+
+
 /**************************************************************************
  *
  * Event queue processing