Call efx_set_channels() before efx->type->dimension_resources()

When using the "separate_tx_channels=1" module parameter, the TX queues are
initially numbered starting from the first TX-only channel number (after all the
RX-only channels).  efx_set_channels() renumbers the queues so that they are
indexed from zero.

On EF10, the TX queues need to be relabelled in this way before calling the
dimension_resources NIC type operation, otherwise the TX queue PIO buffers can be
linked to the wrong VIs when using "separate_tx_channels=1".

Added comments to explain UC/WC mappings for PIO buffers

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index 651626e..21c20ea 100644 (file)
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -565,10 +565,17 @@ static int efx_ef10_dimension_resources(struct efx_nic *efx)
         * several of each (in fact that's the only option if host
         * page size is >4K).  So we may allocate some extra VIs just
         * for writing PIO buffers through.
+        *
+        * The UC mapping contains (min_vis - 1) complete VIs and the
+        * first half of the next VI.  Then the WC mapping begins with
+        * the second half of this last VI.
         */
        uc_mem_map_size = PAGE_ALIGN((min_vis - 1) * EFX_VI_PAGE_SIZE +
                                     ER_DZ_TX_PIOBUF);
        if (nic_data->n_piobufs) {
+               /* pio_write_vi_base rounds down to give the number of complete
+                * VIs inside the UC mapping.
+                */
                pio_write_vi_base = uc_mem_map_size / EFX_VI_PAGE_SIZE;
                wc_mem_map_size = (PAGE_ALIGN((pio_write_vi_base +
                                               nic_data->n_piobufs) *

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 52589f6..57b971e 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1599,6 +1599,8 @@ static int efx_probe_nic(struct efx_nic *efx)
        if (rc)
                goto fail1;
 
+       efx_set_channels(efx);
+
        rc = efx->type->dimension_resources(efx);
        if (rc)
                goto fail2;
@@ -1609,7 +1611,6 @@ static int efx_probe_nic(struct efx_nic *efx)
                efx->rx_indir_table[i] =
                        ethtool_rxfh_indir_default(i, efx->rss_spread);
 
-       efx_set_channels(efx);
        netif_set_real_num_tx_queues(efx->net_dev, efx->n_tx_channels);
        netif_set_real_num_rx_queues(efx->net_dev, efx->n_rx_channels);