sfc: Make queue flushes more reliable

Increase the potential retry count for RX flushes from 5 to 100.

Stop polling the RX_DESC_PTR_TBL to infer that a flush might have
happened. Instead absolutely rely on the flush events, unless bug 7803
applies (Falcon rev A only).

To keep things quick, request flushes for every TX and RX queue up
front, and match up the events to requests.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index be3d2ba3b74e..868ad1e703f1 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -160,6 +160,7 @@ struct efx_tx_buffer {
  * @channel: The associated channel
  * @buffer: The software buffer ring
  * @txd: The hardware descriptor ring
+ * @flushed: Used when handling queue flushing
  * @read_count: Current read pointer.
  *      This is the number of buffers that have been removed from both rings.
  * @stopped: Stopped count.
@@ -192,6 +193,7 @@ struct efx_tx_queue {
         struct efx_nic *nic;
         struct efx_tx_buffer *buffer;
         struct efx_special_buffer txd;
+        bool flushed;
 
         /* Members used mainly on the completion path */
         unsigned int read_count ____cacheline_aligned_in_smp;
@@ -260,6 +262,7 @@ struct efx_rx_buffer {
  *      the remaining space in the allocation.
  * @buf_dma_addr: Page's DMA address.
  * @buf_data: Page's host address.
+ * @flushed: Use when handling queue flushing
  */
 struct efx_rx_queue {
         struct efx_nic *efx;
@@ -285,6 +288,7 @@ struct efx_rx_queue {
         struct page *buf_page;
         dma_addr_t buf_dma_addr;
         char *buf_data;
+        bool flushed;
 };
 
 /**