From de5fb0a053482d89262c3284b67884cd2c621adc Mon Sep 17 00:00:00 2001 From: Frank Li Date: Sun, 3 Mar 2013 17:34:25 +0000 Subject: [PATCH] net: fec: put tx to napi poll function to fix dead lock up stack ndo_start_xmit already hold lock. fec_enet_start_xmit needn't spin lock. stat_xmit just update fep->cur_tx fec_enet_tx just update fep->dirty_tx Reserve a empty bdb to check full or empty cur_tx == dirty_tx means full cur_tx == dirty_tx +1 means empty So needn't is_full variable. Fix spin lock deadlock ================================= [ INFO: inconsistent lock state ] 3.8.0-rc5+ #107 Not tainted --------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. ptp4l/615 [HC1[1]:SC0[0]:HE0:SE1] takes: (&(&list->lock)->rlock#3){?.-...}, at: [<8042c3c4>] skb_queue_tail+0x20/0x50 {HARDIRQ-ON-W} state was registered at: [<80067250>] mark_lock+0x154/0x4e8 [<800676f4>] mark_irqflags+0x110/0x1a4 [<80069208>] __lock_acquire+0x494/0x9c0 [<80069ce8>] lock_acquire+0x90/0xa4 [<80527ad0>] _raw_spin_lock_bh+0x44/0x54 [<804877e0>] first_packet_length+0x38/0x1f0 [<804879e4>] udp_poll+0x4c/0x5c [<804231f8>] sock_poll+0x24/0x28 [<800d27f0>] do_poll.isra.10+0x120/0x254 [<800d36e4>] do_sys_poll+0x15c/0x1e8 [<800d3828>] sys_poll+0x60/0xc8 [<8000e780>] ret_fast_syscall+0x0/0x3c *** DEADLOCK *** 1 lock held by ptp4l/615: #0: (&(&fep->hw_lock)->rlock){-.-...}, at: [<80355f9c>] fec_enet_tx+0x24/0x268 stack backtrace: Backtrace: [<800121e0>] (dump_backtrace+0x0/0x10c) from [<80516210>] (dump_stack+0x18/0x1c) r6:8063b1fc r5:bf38b2f8 r4:bf38b000 r3:bf38b000 [<805161f8>] (dump_stack+0x0/0x1c) from [<805189d0>] (print_usage_bug.part.34+0x164/0x1a4) [<8051886c>] (print_usage_bug.part.34+0x0/0x1a4) from [<80518a88>] (print_usage_bug+0x78/0x88) r8:80065664 r7:bf38b2f8 r6:00000002 r5:00000000 r4:bf38b000 [<80518a10>] (print_usage_bug+0x0/0x88) from [<80518b58>] (mark_lock_irq+0xc0/0x270) r7:bf38b000 r6:00000002 r5:bf38b2f8 r4:00000000 [<80518a98>] (mark_lock_irq+0x0/0x270) from [<80067270>] (mark_lock+0x174/0x4e8) [<800670fc>] (mark_lock+0x0/0x4e8) from [<80067744>] (mark_irqflags+0x160/0x1a4) [<800675e4>] (mark_irqflags+0x0/0x1a4) from [<80069208>] (__lock_acquire+0x494/0x9c0) r5:00000002 r4:bf38b2f8 [<80068d74>] (__lock_acquire+0x0/0x9c0) from [<80069ce8>] (lock_acquire+0x90/0xa4) [<80069c58>] (lock_acquire+0x0/0xa4) from [<805278d8>] (_raw_spin_lock_irqsave+0x4c/0x60) [<8052788c>] (_raw_spin_lock_irqsave+0x0/0x60) from [<8042c3c4>] (skb_queue_tail+0x20/0x50) r6:bfbb2180 r5:bf1d0190 r4:bf1d0184 [<8042c3a4>] (skb_queue_tail+0x0/0x50) from [<8042c4cc>] (sock_queue_err_skb+0xd8/0x188) r6:00000056 r5:bfbb2180 r4:bf1d0000 r3:00000000 [<8042c3f4>] (sock_queue_err_skb+0x0/0x188) from [<8042d15c>] (skb_tstamp_tx+0x70/0xa0) r6:bf0dddb0 r5:bf1d0000 r4:bfbb2180 r3:00000004 [<8042d0ec>] (skb_tstamp_tx+0x0/0xa0) from [<803561d0>] (fec_enet_tx+0x258/0x268) r6:c089d260 r5:00001c00 r4:bfbd0000 [<80355f78>] (fec_enet_tx+0x0/0x268) from [<803562cc>] (fec_enet_interrupt+0xec/0xf8) [<803561e0>] (fec_enet_interrupt+0x0/0xf8) from [<8007d5b0>] (handle_irq_event_percpu+0x54/0x1a0) [<8007d55c>] (handle_irq_event_percpu+0x0/0x1a0) from [<8007d740>] (handle_irq_event+0x44/0x64) [<8007d6fc>] (handle_irq_event+0x0/0x64) from [<80080690>] (handle_fasteoi_irq+0xc4/0x15c) r6:bf0dc000 r5:bf811290 r4:bf811240 r3:00000000 [<800805cc>] (handle_fasteoi_irq+0x0/0x15c) from [<8007ceec>] (generic_handle_irq+0x28/0x38) r5:807130c8 r4:00000096 [<8007cec4>] (generic_handle_irq+0x0/0x38) from [<8000f16c>] (handle_IRQ+0x54/0xb4) r4:8071d280 r3:00000180 [<8000f118>] (handle_IRQ+0x0/0xb4) from [<80008544>] (gic_handle_irq+0x30/0x64) r8:8000e924 r7:f4000100 r6:bf0ddef8 r5:8071c974 r4:f400010c r3:00000000 [<80008514>] (gic_handle_irq+0x0/0x64) from [<8000e2e4>] (__irq_svc+0x44/0x5c) Exception stack(0xbf0ddef8 to 0xbf0ddf40) Signed-off-by: Frank Li Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec.c | 85 ++++++++++++++-------------- drivers/net/ethernet/freescale/fec.h | 3 - 2 files changed, 41 insertions(+), 47 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c index fccc3bf2141d..069a155d16ed 100644 --- a/drivers/net/ethernet/freescale/fec.c +++ b/drivers/net/ethernet/freescale/fec.c @@ -246,14 +246,13 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) struct bufdesc *bdp; void *bufaddr; unsigned short status; - unsigned long flags; + unsigned int index; if (!fep->link) { /* Link is down or autonegotiation is in progress. */ return NETDEV_TX_BUSY; } - spin_lock_irqsave(&fep->hw_lock, flags); /* Fill in a Tx ring entry */ bdp = fep->cur_tx; @@ -264,7 +263,6 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) * This should not happen, since ndev->tbusy should be set. */ printk("%s: tx queue full!.\n", ndev->name); - spin_unlock_irqrestore(&fep->hw_lock, flags); return NETDEV_TX_BUSY; } @@ -280,13 +278,13 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) * 4-byte boundaries. Use bounce buffers to copy data * and get it aligned. Ugh. */ + if (fep->bufdesc_ex) + index = (struct bufdesc_ex *)bdp - + (struct bufdesc_ex *)fep->tx_bd_base; + else + index = bdp - fep->tx_bd_base; + if (((unsigned long) bufaddr) & FEC_ALIGNMENT) { - unsigned int index; - if (fep->bufdesc_ex) - index = (struct bufdesc_ex *)bdp - - (struct bufdesc_ex *)fep->tx_bd_base; - else - index = bdp - fep->tx_bd_base; memcpy(fep->tx_bounce[index], skb->data, skb->len); bufaddr = fep->tx_bounce[index]; } @@ -300,10 +298,7 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) swap_buffer(bufaddr, skb->len); /* Save skb pointer */ - fep->tx_skbuff[fep->skb_cur] = skb; - - ndev->stats.tx_bytes += skb->len; - fep->skb_cur = (fep->skb_cur+1) & TX_RING_MOD_MASK; + fep->tx_skbuff[index] = skb; /* Push the data cache so the CPM does not get stale memory * data. @@ -331,26 +326,22 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) ebdp->cbd_esc = BD_ENET_TX_INT; } } - /* Trigger transmission start */ - writel(0, fep->hwp + FEC_X_DES_ACTIVE); - /* If this was the last BD in the ring, start at the beginning again. */ if (status & BD_ENET_TX_WRAP) bdp = fep->tx_bd_base; else bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); - if (bdp == fep->dirty_tx) { - fep->tx_full = 1; + fep->cur_tx = bdp; + + if (fep->cur_tx == fep->dirty_tx) netif_stop_queue(ndev); - } - fep->cur_tx = bdp; + /* Trigger transmission start */ + writel(0, fep->hwp + FEC_X_DES_ACTIVE); skb_tx_timestamp(skb); - spin_unlock_irqrestore(&fep->hw_lock, flags); - return NETDEV_TX_OK; } @@ -406,11 +397,8 @@ fec_restart(struct net_device *ndev, int duplex) writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc) * RX_RING_SIZE, fep->hwp + FEC_X_DES_START); - fep->dirty_tx = fep->cur_tx = fep->tx_bd_base; fep->cur_rx = fep->rx_bd_base; - /* Reset SKB transmit buffers. */ - fep->skb_cur = fep->skb_dirty = 0; for (i = 0; i <= TX_RING_MOD_MASK; i++) { if (fep->tx_skbuff[i]) { dev_kfree_skb_any(fep->tx_skbuff[i]); @@ -573,20 +561,35 @@ fec_enet_tx(struct net_device *ndev) struct bufdesc *bdp; unsigned short status; struct sk_buff *skb; + int index = 0; fep = netdev_priv(ndev); - spin_lock(&fep->hw_lock); bdp = fep->dirty_tx; + /* get next bdp of dirty_tx */ + if (bdp->cbd_sc & BD_ENET_TX_WRAP) + bdp = fep->tx_bd_base; + else + bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex); + while (((status = bdp->cbd_sc) & BD_ENET_TX_READY) == 0) { - if (bdp == fep->cur_tx && fep->tx_full == 0) + + /* current queue is empty */ + if (bdp == fep->cur_tx) break; + if (fep->bufdesc_ex) + index = (struct bufdesc_ex *)bdp - + (struct bufdesc_ex *)fep->tx_bd_base; + else + index = bdp - fep->tx_bd_base; + dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr, FEC_ENET_TX_FRSIZE, DMA_TO_DEVICE); bdp->cbd_bufaddr = 0; - skb = fep->tx_skbuff[fep->skb_dirty]; + skb = fep->tx_skbuff[index]; + /* Check for errors. */ if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN | @@ -631,8 +634,9 @@ fec_enet_tx(struct net_device *ndev) /* Free the sk buffer associated with this last transmit */ dev_kfree_skb_any(skb); - fep->tx_skbuff[fep->skb_dirty] = NULL; - fep->skb_dirty = (fep->skb_dirty + 1) & TX_RING_MOD_MASK; + fep->tx_skbuff[index] = NULL; + + fep->dirty_tx = bdp; /* Update pointer to next buffer descriptor to be transmitted */ if (status & BD_ENET_TX_WRAP) @@ -642,14 +646,12 @@ fec_enet_tx(struct net_device *ndev) /* Since we have freed up a buffer, the ring is no longer full */ - if (fep->tx_full) { - fep->tx_full = 0; + if (fep->dirty_tx != fep->cur_tx) { if (netif_queue_stopped(ndev)) netif_wake_queue(ndev); } } - fep->dirty_tx = bdp; - spin_unlock(&fep->hw_lock); + return; } @@ -816,7 +818,7 @@ fec_enet_interrupt(int irq, void *dev_id) int_events = readl(fep->hwp + FEC_IEVENT); writel(int_events, fep->hwp + FEC_IEVENT); - if (int_events & FEC_ENET_RXF) { + if (int_events & (FEC_ENET_RXF | FEC_ENET_TXF)) { ret = IRQ_HANDLED; /* Disable the RX interrupt */ @@ -827,15 +829,6 @@ fec_enet_interrupt(int irq, void *dev_id) } } - /* Transmit OK, or non-fatal error. Update the buffer - * descriptors. FEC handles all errors, we just discover - * them as part of the transmit process. - */ - if (int_events & FEC_ENET_TXF) { - ret = IRQ_HANDLED; - fec_enet_tx(ndev); - } - if (int_events & FEC_ENET_MII) { ret = IRQ_HANDLED; complete(&fep->mdio_done); @@ -851,6 +844,8 @@ static int fec_enet_rx_napi(struct napi_struct *napi, int budget) int pkts = fec_enet_rx(ndev, budget); struct fec_enet_private *fep = netdev_priv(ndev); + fec_enet_tx(ndev); + if (pkts < budget) { napi_complete(napi); writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK); @@ -1646,6 +1641,7 @@ static int fec_enet_init(struct net_device *ndev) /* ...and the same for transmit */ bdp = fep->tx_bd_base; + fep->cur_tx = bdp; for (i = 0; i < TX_RING_SIZE; i++) { /* Initialize the BD for every fragment in the page. */ @@ -1657,6 +1653,7 @@ static int fec_enet_init(struct net_device *ndev) /* Set the last buffer to wrap */ bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex); bdp->cbd_sc |= BD_SC_WRAP; + fep->dirty_tx = bdp; fec_restart(ndev, 0); diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h index 01579b8e37c4..c0f63be91ff7 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -214,8 +214,6 @@ struct fec_enet_private { unsigned char *tx_bounce[TX_RING_SIZE]; struct sk_buff *tx_skbuff[TX_RING_SIZE]; struct sk_buff *rx_skbuff[RX_RING_SIZE]; - ushort skb_cur; - ushort skb_dirty; /* CPM dual port RAM relative addresses */ dma_addr_t bd_dma; @@ -227,7 +225,6 @@ struct fec_enet_private { /* The ring entries to be free()ed */ struct bufdesc *dirty_tx; - uint tx_full; /* hold while accessing the HW like ringbuffer for tx/rx but not MAC */ spinlock_t hw_lock; -- GitLab