| From d9317aea16ecec7694271ef11fb7791a0f0d9cc5 Mon Sep 17 00:00:00 2001 |
| From: Ben Hutchings <bhutchings@solarflare.com> |
| Date: Thu, 23 Jan 2014 14:35:48 +0000 |
| Subject: sfc: Use the correct maximum TX DMA ring size for SFC9100 |
| |
| From: Ben Hutchings <bhutchings@solarflare.com> |
| |
| commit d9317aea16ecec7694271ef11fb7791a0f0d9cc5 upstream. |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/net/ethernet/sfc/efx.h | 3 +++ |
| drivers/net/ethernet/sfc/ethtool.c | 4 ++-- |
| 2 files changed, 5 insertions(+), 2 deletions(-) |
| |
| --- 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_r |
| #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 */ |
| |
| /** |
| --- a/drivers/net/ethernet/sfc/ethtool.c |
| +++ b/drivers/net/ethernet/sfc/ethtool.c |
| @@ -583,7 +583,7 @@ static void efx_ethtool_get_ringparam(st |
| 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; |
| } |
| @@ -596,7 +596,7 @@ static int efx_ethtool_set_ringparam(str |
| |
| 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) { |
