Message ID | 4E1F242E.7070509@infradead.org |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Geoff Levand <geoff@infradead.org> Date: Thu, 14 Jul 2011 10:15:26 -0700 > Fix the condition where PS3 network RX hangs when no network > TX is occurring by calling gelic_card_enable_rxdmac() during > RX_DMA_CHAIN_END event processing. > > The gelic hardware automatically clears its RX_DMA_EN flag when > it detects an RX_DMA_CHAIN_END event. In its processing of > RX_DMA_CHAIN_END the gelic driver is required to set RX_DMA_EN > (with a call to gelic_card_enable_rxdmac()) to restart RX DMA > transfers. The existing gelic driver code does not set > RX_DMA_EN directly in its processing of the RX_DMA_CHAIN_END > event, but uses a flag variable card->rx_dma_restart_required > to schedule the setting of RX_DMA_EN until next inside the > interrupt handler. > > It seems this delayed setting of RX_DMA_EN causes the hang since > the next RX interrupt after the RX_DMA_CHAIN_END event where > RX_DMA_EN is scheduled to be set will not occur since RX_DMA_EN > was not set. In the case were network TX is occuring, RX_DMA_EN > is set in the next TX interrupt and RX processing continues. > > Signed-off-by: Geoff Levand <geoff@infradead.org> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/drivers/net/ps3_gelic_net.c +++ b/drivers/net/ps3_gelic_net.c @@ -986,10 +986,6 @@ static int gelic_card_decode_one_descr(s int dmac_chain_ended; status = gelic_descr_get_status(descr); - /* is this descriptor terminated with next_descr == NULL? */ - dmac_chain_ended = - be32_to_cpu(descr->dmac_cmd_status) & - GELIC_DESCR_RX_DMA_CHAIN_END; if (status == GELIC_DESCR_DMA_CARDOWNED) return 0; @@ -1052,6 +1048,11 @@ static int gelic_card_decode_one_descr(s /* ok, we've got a packet in descr */ gelic_net_pass_skb_up(descr, card, netdev); refill: + + /* is the current descriptor terminated with next_descr == NULL? */ + dmac_chain_ended = + be32_to_cpu(descr->dmac_cmd_status) & + GELIC_DESCR_RX_DMA_CHAIN_END; /* * So that always DMAC can see the end * of the descriptor chain to avoid @@ -1080,10 +1081,9 @@ refill: * If dmac chain was met, DMAC stopped. * thus re-enable it */ - if (dmac_chain_ended) { - card->rx_dma_restart_required = 1; - dev_dbg(ctodev(card), "reenable rx dma scheduled\n"); - } + + if (dmac_chain_ended) + gelic_card_enable_rxdmac(card); return 1; } @@ -1149,11 +1149,6 @@ static irqreturn_t gelic_card_interrupt( status &= card->irq_mask; - if (card->rx_dma_restart_required) { - card->rx_dma_restart_required = 0; - gelic_card_enable_rxdmac(card); - } - if (status & GELIC_CARD_RXINT) { gelic_card_rx_irq_off(card); napi_schedule(&card->napi); --- a/drivers/net/ps3_gelic_net.h +++ b/drivers/net/ps3_gelic_net.h @@ -289,7 +289,6 @@ struct gelic_card { struct gelic_descr_chain tx_chain; struct gelic_descr_chain rx_chain; - int rx_dma_restart_required; /* * tx_lock guards tx descriptor list and * tx_dma_progress.
Fix the condition where PS3 network RX hangs when no network TX is occurring by calling gelic_card_enable_rxdmac() during RX_DMA_CHAIN_END event processing. The gelic hardware automatically clears its RX_DMA_EN flag when it detects an RX_DMA_CHAIN_END event. In its processing of RX_DMA_CHAIN_END the gelic driver is required to set RX_DMA_EN (with a call to gelic_card_enable_rxdmac()) to restart RX DMA transfers. The existing gelic driver code does not set RX_DMA_EN directly in its processing of the RX_DMA_CHAIN_END event, but uses a flag variable card->rx_dma_restart_required to schedule the setting of RX_DMA_EN until next inside the interrupt handler. It seems this delayed setting of RX_DMA_EN causes the hang since the next RX interrupt after the RX_DMA_CHAIN_END event where RX_DMA_EN is scheduled to be set will not occur since RX_DMA_EN was not set. In the case were network TX is occuring, RX_DMA_EN is set in the next TX interrupt and RX processing continues. Signed-off-by: Geoff Levand <geoff@infradead.org> --- drivers/net/ps3_gelic_net.c | 21 ++++++++------------- drivers/net/ps3_gelic_net.h | 1 - 2 files changed, 8 insertions(+), 14 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html