From fd371e32fe53f137a0f940d61772bda92180007b Mon Sep 17 00:00:00 2001 From: Steve Hodgson Date: Tue, 1 Jun 2010 11:17:51 +0000 Subject: [PATCH] sfc: Workaround flush failures on Falcon B0 Under certain conditions a PHY may backpressure Falcon B0 in such a way that flushes timeout. In normal circumstances the phy poller would fix the PHY, and the flush could complete. But efx_nic_flush_queues() is always called after efx_stop_all(), so the poller has been stopped. Even if this weren't the case, how long would we have to wait for the poller to fix this? And several callers of efx_nic_flush_queues() are about to reset the device anyway - so we don't need to do anything. Work around this bug by scheduling a reset. Ensure that the MAC is never rewired back into the datapath before the reset runs (we already ignore all rx events anyway). Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/sfc/efx.c | 13 +++++++++++-- drivers/net/sfc/falcon.c | 8 +++++--- drivers/net/sfc/nic.c | 3 --- drivers/net/sfc/workarounds.h | 2 +- 4 files changed, 17 insertions(+), 9 deletions(-) diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c index 0319000379e1..d1a1d32e73ee 100644 --- a/drivers/net/sfc/efx.c +++ b/drivers/net/sfc/efx.c @@ -27,6 +27,7 @@ #include "nic.h" #include "mcdi.h" +#include "workarounds.h" /************************************************************************** * @@ -556,10 +557,18 @@ static void efx_fini_channels(struct efx_nic *efx) BUG_ON(efx->port_enabled); rc = efx_nic_flush_queues(efx); - if (rc) + if (rc && EFX_WORKAROUND_7803(efx)) { + /* Schedule a reset to recover from the flush failure. The + * descriptor caches reference memory we're about to free, + * but falcon_reconfigure_mac_wrapper() won't reconnect + * the MACs because of the pending reset. */ + EFX_ERR(efx, "Resetting to recover from flush failure\n"); + efx_schedule_reset(efx, RESET_TYPE_ALL); + } else if (rc) { EFX_ERR(efx, "failed to flush queues\n"); - else + } else { EFX_LOG(efx, "successfully flushed all queues\n"); + } efx_for_each_channel(channel, efx) { EFX_LOG(channel->efx, "shut down chan %d\n", channel->channel); diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c index 655b697b45b2..8558865ff380 100644 --- a/drivers/net/sfc/falcon.c +++ b/drivers/net/sfc/falcon.c @@ -548,7 +548,9 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx) { struct efx_link_state *link_state = &efx->link_state; efx_oword_t reg; - int link_speed; + int link_speed, isolate; + + isolate = (efx->reset_pending != RESET_TYPE_NONE); switch (link_state->speed) { case 10000: link_speed = 3; break; @@ -570,7 +572,7 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx) * discarded. */ if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0) { EFX_SET_OWORD_FIELD(reg, FRF_BB_TXFIFO_DRAIN_EN, - !link_state->up); + !link_state->up || isolate); } efx_writeo(efx, ®, FR_AB_MAC_CTRL); @@ -584,7 +586,7 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx) EFX_SET_OWORD_FIELD(reg, FRF_AZ_RX_XOFF_MAC_EN, 1); /* Unisolate the MAC -> RX */ if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0) - EFX_SET_OWORD_FIELD(reg, FRF_BZ_RX_INGR_EN, 1); + EFX_SET_OWORD_FIELD(reg, FRF_BZ_RX_INGR_EN, !isolate); efx_writeo(efx, ®, FR_AZ_RX_CFG); } diff --git a/drivers/net/sfc/nic.c b/drivers/net/sfc/nic.c index 5d3aaec58556..ec0bb80f5ae8 100644 --- a/drivers/net/sfc/nic.c +++ b/drivers/net/sfc/nic.c @@ -1219,9 +1219,6 @@ int efx_nic_flush_queues(struct efx_nic *efx) rx_queue->flushed = FLUSH_DONE; } - if (EFX_WORKAROUND_7803(efx)) - return 0; - return -ETIMEDOUT; } diff --git a/drivers/net/sfc/workarounds.h b/drivers/net/sfc/workarounds.h index 518f7fc91473..782e45a613d6 100644 --- a/drivers/net/sfc/workarounds.h +++ b/drivers/net/sfc/workarounds.h @@ -54,7 +54,7 @@ /* Increase filter depth to avoid RX_RESET */ #define EFX_WORKAROUND_7244 EFX_WORKAROUND_FALCON_A /* Flushes may never complete */ -#define EFX_WORKAROUND_7803 EFX_WORKAROUND_FALCON_A +#define EFX_WORKAROUND_7803 EFX_WORKAROUND_FALCON_AB /* Leak overlength packets rather than free */ #define EFX_WORKAROUND_8071 EFX_WORKAROUND_FALCON_A -- 2.30.2