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authorBen Hutchings <bhutchings@solarflare.com>2014-01-23 14:35:48 +0000
committerDavid S. Miller <davem@davemloft.net>2014-01-23 13:40:51 -0800
commitd9317aea16ecec7694271ef11fb7791a0f0d9cc5 (patch)
tree9c1905eeb0c2a503acefcacf9743192da030dc6a
parent8533ccf3e78bc9ca17543c0109ff832351f88d51 (diff)
sfc: Use the correct maximum TX DMA ring size for SFC9100
As part of a workaround for a hardware erratum in the SFC9100 family (SF bug 35388), the TX_DESC_UPD_DWORD register address is also used for communicating with the event block, and only descriptor pointer values < 2048 are valid. If the TX DMA ring size is increased to 4096 descriptors (which the firmware still allows) then we may write a descriptor pointer value >= 2048, which has entirely different and undesirable effects! Limit the TX DMA ring size correctly when this workaround is in effect. Fixes: 8127d661e77f ('sfc: Add support for Solarflare SFC9100 family') Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Shradha Shah <sshah@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/sfc/efx.h3
-rw-r--r--drivers/net/ethernet/sfc/ethtool.c4
2 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h
index 601224736b9b..dbd7b78fe01c 100644
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -66,6 +66,9 @@ void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue);
#define EFX_RXQ_MIN_ENT 128U
#define EFX_TXQ_MIN_ENT(efx) (2 * efx_tx_max_skb_descs(efx))
+#define EFX_TXQ_MAX_ENT(efx) (EFX_WORKAROUND_35388(efx) ? \
+ EFX_MAX_DMAQ_SIZE / 2 : EFX_MAX_DMAQ_SIZE)
+
/* Filters */
/**
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index f181522688b2..229428915aa8 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -591,7 +591,7 @@ static void efx_ethtool_get_ringparam(struct net_device *net_dev,
struct efx_nic *efx = netdev_priv(net_dev);
ring->rx_max_pending = EFX_MAX_DMAQ_SIZE;
- ring->tx_max_pending = EFX_MAX_DMAQ_SIZE;
+ ring->tx_max_pending = EFX_TXQ_MAX_ENT(efx);
ring->rx_pending = efx->rxq_entries;
ring->tx_pending = efx->txq_entries;
}
@@ -604,7 +604,7 @@ static int efx_ethtool_set_ringparam(struct net_device *net_dev,
if (ring->rx_mini_pending || ring->rx_jumbo_pending ||
ring->rx_pending > EFX_MAX_DMAQ_SIZE ||
- ring->tx_pending > EFX_MAX_DMAQ_SIZE)
+ ring->tx_pending > EFX_TXQ_MAX_ENT(efx))
return -EINVAL;
if (ring->rx_pending < EFX_RXQ_MIN_ENT) {