From 763c067152ac8f8acc6a4920bd335254435feb2b Mon Sep 17 00:00:00 2001 From: florian Date: Fri, 16 Nov 2012 16:32:55 +0000 Subject: [leon] move patches to patches-2.6.36 Signed-off-by: Florian Fainelli git-svn-id: svn://svn.openwrt.org/openwrt/trunk@34220 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- .../024-greth_resolve_smp_and_other_issues.patch | 399 --------------------- 1 file changed, 399 deletions(-) delete mode 100644 target/linux/leon/patches/024-greth_resolve_smp_and_other_issues.patch (limited to 'target/linux/leon/patches/024-greth_resolve_smp_and_other_issues.patch') diff --git a/target/linux/leon/patches/024-greth_resolve_smp_and_other_issues.patch b/target/linux/leon/patches/024-greth_resolve_smp_and_other_issues.patch deleted file mode 100644 index c2293cae0..000000000 --- a/target/linux/leon/patches/024-greth_resolve_smp_and_other_issues.patch +++ /dev/null @@ -1,399 +0,0 @@ -From 4439d933884ee3c7e320b8d33bd2e268dd5b6fa5 Mon Sep 17 00:00:00 2001 -From: Daniel Hellstrom -Date: Wed, 1 Dec 2010 11:40:19 +0100 -Subject: [PATCH] GRETH: resolve SMP issues and other problems - -Fixes the following: -1. POLL should not enable IRQ when work is not completed -2. No locking between TX descriptor cleaning and XMIT descriptor handling -3. No locking between RX POLL and XMIT modifying control register -4. Since TX cleaning (called from POLL) is running in parallel with XMIT - unnecessary locking is needed. -5. IRQ handler looks at RX frame status solely, this is wrong when IRQ is - temporarily disabled (in POLL), and when IRQ is shared. -6. IRQ handler clears IRQ status, which is unnecessary -7. TX queue was stopped in preventing cause when not MAX_SKB_FRAGS+1 descriptors - were available after a SKB been scheduled by XMIT. Instead the TX queue is - stopped first when not enough descriptors are available upon entering XMIT. - -It was hard to split up this patch in smaller pieces since all are tied -together somehow. - -Note the RX flag used in the interrupt handler does not signal that interrtupt -was asserted, but that a frame was received. Same goes for TX. Also, IRQ is not -asserted when the RX flag is set before enabling IRQ enable until a new frame is -received. So extra care must be taken to avoid enabling IRQ and all descriptors -are already used, hence dead lock will upon us. See new POLL implementation that -enableds IRQ then look at the RX flag to determine if one or more IRQs may have -been missed. TX/RX flags are cleared before handling previously enabled -descriptors, this ensures that the RX/TX flags are valid when determining if IRQ -should be turned on again. - -By moving TX cleaning from POLL to XMIT in the standard case, removes some -locking trouble. Enabling TX cleaning from poll only when not enough TX -descriptors are available is safe because the TX queue is at the same time -stopped, thus XMIT will not be called. The TX queue is woken up again when -enough descriptrs are available. - -TX Frames are always enabled with IRQ, however the TX IRQ Enable flag will not -be enabled until XMIT must wait for free descriptors. - -Locking RX and XMIT parts of the driver from each other is needed because the -RX/TX enable bits share the same register. - -Signed-off-by: Daniel Hellstrom ---- - drivers/net/greth.c | 158 ++++++++++++++++++++++++++++++--------------------- - 1 files changed, 93 insertions(+), 65 deletions(-) - ---- a/drivers/net/greth.c -+++ b/drivers/net/greth.c -@@ -1,7 +1,7 @@ - /* - * Aeroflex Gaisler GRETH 10/100/1G Ethernet MAC. - * -- * 2005-2009 (c) Aeroflex Gaisler AB -+ * 2005-2010 (c) Aeroflex Gaisler AB - * - * This driver supports GRETH 10/100 and GRETH 10/100/1G Ethernet MACs - * available in the GRLIB VHDL IP core library. -@@ -401,12 +401,20 @@ greth_start_xmit(struct sk_buff *skb, st - struct greth_private *greth = netdev_priv(dev); - struct greth_bd *bdp; - int err = NETDEV_TX_OK; -- u32 status, dma_addr; -+ u32 status, dma_addr, ctrl; -+ unsigned long flags; - -- bdp = greth->tx_bd_base + greth->tx_next; -+ /* Clean TX Ring */ -+ greth_clean_tx(greth->netdev); - - if (unlikely(greth->tx_free <= 0)) { -+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/ -+ ctrl = GRETH_REGLOAD(greth->regs->control); -+ /* Enable TX IRQ only if not already in poll() routine */ -+ if ( ctrl & GRETH_RXI ) -+ GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI); - netif_stop_queue(dev); -+ spin_unlock_irqrestore(&greth->devlock, flags); - return NETDEV_TX_BUSY; - } - -@@ -419,13 +427,14 @@ greth_start_xmit(struct sk_buff *skb, st - goto out; - } - -+ bdp = greth->tx_bd_base + greth->tx_next; - dma_addr = greth_read_bd(&bdp->addr); - - memcpy((unsigned char *) phys_to_virt(dma_addr), skb->data, skb->len); - - dma_sync_single_for_device(greth->dev, dma_addr, skb->len, DMA_TO_DEVICE); - -- status = GRETH_BD_EN | (skb->len & GRETH_BD_LEN); -+ status = GRETH_BD_EN | GRETH_BD_IE | (skb->len & GRETH_BD_LEN); - - /* Wrap around descriptor ring */ - if (greth->tx_next == GRETH_TXBD_NUM_MASK) { -@@ -435,22 +444,11 @@ greth_start_xmit(struct sk_buff *skb, st - greth->tx_next = NEXT_TX(greth->tx_next); - greth->tx_free--; - -- /* No more descriptors */ -- if (unlikely(greth->tx_free == 0)) { -- -- /* Free transmitted descriptors */ -- greth_clean_tx(dev); -- -- /* If nothing was cleaned, stop queue & wait for irq */ -- if (unlikely(greth->tx_free == 0)) { -- status |= GRETH_BD_IE; -- netif_stop_queue(dev); -- } -- } -- - /* Write descriptor control word and enable transmission */ - greth_write_bd(&bdp->stat, status); -+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/ - greth_enable_tx(greth); -+ spin_unlock_irqrestore(&greth->devlock, flags); - - out: - dev_kfree_skb(skb); -@@ -463,13 +461,24 @@ greth_start_xmit_gbit(struct sk_buff *sk - { - struct greth_private *greth = netdev_priv(dev); - struct greth_bd *bdp; -- u32 status = 0, dma_addr; -+ u32 status = 0, dma_addr, ctrl; - int curr_tx, nr_frags, i, err = NETDEV_TX_OK; -+ unsigned long flags; - - nr_frags = skb_shinfo(skb)->nr_frags; - -+ /* Clean TX Ring */ -+ greth_clean_tx_gbit(dev); -+ - if (greth->tx_free < nr_frags + 1) { -+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/ -+ ctrl = GRETH_REGLOAD(greth->regs->control); -+ /* Enable TX IRQ only if not already in poll() routine */ -+ if ( ctrl & GRETH_RXI ) { -+ GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_TXI); -+ } - netif_stop_queue(dev); -+ spin_unlock_irqrestore(&greth->devlock, flags); - err = NETDEV_TX_BUSY; - goto out; - } -@@ -522,14 +531,8 @@ greth_start_xmit_gbit(struct sk_buff *sk - /* More fragments left */ - if (i < nr_frags - 1) - status |= GRETH_TXBD_MORE; -- -- /* ... last fragment, check if out of descriptors */ -- else if (greth->tx_free - nr_frags - 1 < (MAX_SKB_FRAGS + 1)) { -- -- /* Enable interrupts and stop queue */ -- status |= GRETH_BD_IE; -- netif_stop_queue(dev); -- } -+ else -+ status |= GRETH_BD_IE; /* enable IRQ on last fragment */ - - greth_write_bd(&bdp->stat, status); - -@@ -557,7 +560,9 @@ greth_start_xmit_gbit(struct sk_buff *sk - - wmb(); - -+ spin_lock_irqsave(&greth->devlock, flags); /*save from poll/irq*/ - greth_enable_tx(greth); -+ spin_unlock_irqrestore(&greth->devlock, flags); - - return NETDEV_TX_OK; - -@@ -579,12 +584,11 @@ out: - return err; - } - -- - static irqreturn_t greth_interrupt(int irq, void *dev_id) - { - struct net_device *dev = dev_id; - struct greth_private *greth; -- u32 status; -+ u32 status, ctrl; - irqreturn_t retval = IRQ_NONE; - - greth = netdev_priv(dev); -@@ -594,13 +598,14 @@ static irqreturn_t greth_interrupt(int i - /* Get the interrupt events that caused us to be here. */ - status = GRETH_REGLOAD(greth->regs->status); - -- /* Handle rx and tx interrupts through poll */ -- if (status & (GRETH_INT_RE | GRETH_INT_RX | GRETH_INT_TE | GRETH_INT_TX)) { -+ /* Must see if interrupts are enabled also, INT_TX|INT_RX flags may be set regardless -+ * of whether IRQ is enabled or not. Especially important when shared IRQ. -+ */ -+ ctrl = GRETH_REGLOAD(greth->regs->control); - -- /* Clear interrupt status */ -- GRETH_REGSAVE(greth->regs->status, -- status & (GRETH_INT_RE | GRETH_INT_RX | -- GRETH_INT_TE | GRETH_INT_TX)); -+ /* Handle rx and tx interrupts through poll */ -+ if (((status & (GRETH_INT_RE | GRETH_INT_RX)) && (ctrl & GRETH_RXI)) || -+ ((status & (GRETH_INT_TE | GRETH_INT_TX)) && (ctrl & GRETH_TXI))) { - - retval = IRQ_HANDLED; - -@@ -625,6 +630,8 @@ static void greth_clean_tx(struct net_de - - while (1) { - bdp = greth->tx_bd_base + greth->tx_last; -+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX); -+ mb(); - stat = greth_read_bd(&bdp->stat); - - if (unlikely(stat & GRETH_BD_EN)) -@@ -685,7 +692,10 @@ static void greth_clean_tx_gbit(struct n - - /* We only clean fully completed SKBs */ - bdp_last_frag = greth->tx_bd_base + SKIP_TX(greth->tx_last, nr_frags); -- stat = bdp_last_frag->stat; -+ -+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_TE | GRETH_INT_TX); -+ mb(); -+ stat = greth_read_bd(&bdp_last_frag->stat); - - if (stat & GRETH_BD_EN) - break; -@@ -717,23 +727,12 @@ static void greth_clean_tx_gbit(struct n - greth->tx_free += nr_frags+1; - dev_kfree_skb(skb); - } -- if (greth->tx_free > (MAX_SKB_FRAGS + 1)) { -+ -+ if (netif_queue_stopped(dev) && (greth->tx_free > (MAX_SKB_FRAGS + 1))) { - netif_wake_queue(dev); - } - } - --static int greth_pending_packets(struct greth_private *greth) --{ -- struct greth_bd *bdp; -- u32 status; -- bdp = greth->rx_bd_base + greth->rx_cur; -- status = greth_read_bd(&bdp->stat); -- if (status & GRETH_BD_EN) -- return 0; -- else -- return 1; --} -- - static int greth_rx(struct net_device *dev, int limit) - { - struct greth_private *greth; -@@ -742,20 +741,24 @@ static int greth_rx(struct net_device *d - int pkt_len; - int bad, count; - u32 status, dma_addr; -+ unsigned long flags; - - greth = netdev_priv(dev); - - for (count = 0; count < limit; ++count) { - - bdp = greth->rx_bd_base + greth->rx_cur; -+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX); -+ mb(); - status = greth_read_bd(&bdp->stat); -- dma_addr = greth_read_bd(&bdp->addr); -- bad = 0; - - if (unlikely(status & GRETH_BD_EN)) { - break; - } - -+ dma_addr = greth_read_bd(&bdp->addr); -+ bad = 0; -+ - /* Check status for errors. */ - if (unlikely(status & GRETH_RXBD_STATUS)) { - if (status & GRETH_RXBD_ERR_FT) { -@@ -817,7 +820,9 @@ static int greth_rx(struct net_device *d - - dma_sync_single_for_device(greth->dev, dma_addr, MAX_FRAME_SIZE, DMA_FROM_DEVICE); - -+ spin_lock_irqsave(&greth->devlock, flags); /* save from XMIT */ - greth_enable_rx(greth); -+ spin_unlock_irqrestore(&greth->devlock, flags); - - greth->rx_cur = NEXT_RX(greth->rx_cur); - } -@@ -851,6 +856,7 @@ static int greth_rx_gbit(struct net_devi - int pkt_len; - int bad, count = 0; - u32 status, dma_addr; -+ unsigned long flags; - - greth = netdev_priv(dev); - -@@ -858,6 +864,8 @@ static int greth_rx_gbit(struct net_devi - - bdp = greth->rx_bd_base + greth->rx_cur; - skb = greth->rx_skbuff[greth->rx_cur]; -+ GRETH_REGSAVE(greth->regs->status, GRETH_INT_RE | GRETH_INT_RX); -+ mb(); - status = greth_read_bd(&bdp->stat); - bad = 0; - -@@ -940,7 +948,9 @@ static int greth_rx_gbit(struct net_devi - - wmb(); - greth_write_bd(&bdp->stat, status); -+ spin_lock_irqsave(&greth->devlock, flags); - greth_enable_rx(greth); -+ spin_unlock_irqrestore(&greth->devlock, flags); - greth->rx_cur = NEXT_RX(greth->rx_cur); - } - -@@ -952,15 +962,19 @@ static int greth_poll(struct napi_struct - { - struct greth_private *greth; - int work_done = 0; -+ unsigned long flags; -+ u32 mask, ctrl; - greth = container_of(napi, struct greth_private, napi); - -- if (greth->gbit_mac) { -- greth_clean_tx_gbit(greth->netdev); -- } else { -- greth_clean_tx(greth->netdev); -+restart_txrx_poll: -+ if ( netif_queue_stopped(greth->netdev) ) { -+ if (greth->gbit_mac) { -+ greth_clean_tx_gbit(greth->netdev); -+ } else { -+ greth_clean_tx(greth->netdev); -+ } - } - --restart_poll: - if (greth->gbit_mac) { - work_done += greth_rx_gbit(greth->netdev, budget - work_done); - } else { -@@ -969,15 +983,29 @@ restart_poll: - - if (work_done < budget) { - -- napi_complete(napi); -+ spin_lock_irqsave(&greth->devlock, flags); - -- if (greth_pending_packets(greth)) { -- napi_reschedule(napi); -- goto restart_poll; -+ ctrl = GRETH_REGLOAD(greth->regs->control); -+ if (netif_queue_stopped(greth->netdev)) { -+ GRETH_REGSAVE(greth->regs->control, -+ ctrl | GRETH_TXI | GRETH_RXI); -+ mask = GRETH_INT_RX | GRETH_INT_RE | -+ GRETH_INT_TX | GRETH_INT_TE; -+ } else { -+ GRETH_REGSAVE(greth->regs->control, ctrl | GRETH_RXI); -+ mask = GRETH_INT_RX | GRETH_INT_RE; -+ } -+ -+ if (GRETH_REGLOAD(greth->regs->status) & mask) { -+ GRETH_REGSAVE(greth->regs->control, ctrl); -+ spin_unlock_irqrestore(&greth->devlock, flags); -+ goto restart_txrx_poll; -+ } else { -+ __napi_complete(napi); -+ spin_unlock_irqrestore(&greth->devlock, flags); - } - } - -- greth_enable_irqs(greth); - return work_done; - } - -@@ -1172,11 +1200,11 @@ static const struct ethtool_ops greth_et - }; - - static struct net_device_ops greth_netdev_ops = { -- .ndo_open = greth_open, -- .ndo_stop = greth_close, -- .ndo_start_xmit = greth_start_xmit, -- .ndo_set_mac_address = greth_set_mac_add, -- .ndo_validate_addr = eth_validate_addr, -+ .ndo_open = greth_open, -+ .ndo_stop = greth_close, -+ .ndo_start_xmit = greth_start_xmit, -+ .ndo_set_mac_address = greth_set_mac_add, -+ .ndo_validate_addr = eth_validate_addr, - }; - - static inline int wait_for_mdio(struct greth_private *greth) -- cgit v1.2.3