From 2488a54e485bc108ab136e8e3cb95b99e97f68b5 Mon Sep 17 00:00:00 2001 From: Sebastian Siewior Date: Mon, 2 Dec 2013 10:52:55 +0100 Subject: net: fec_main: dma_map() only the length of the skb On tx submit the driver always dma_map_single() FEC_ENET_TX_FRSIZE (=2048) bytes. This works because we don't overwrite any memory after the data buffer, we remove it from cache if it was there. So we hurt performace in case the mapping of a smaller area makes a difference. There is also a bug: If the data area starts shortly before the end of RAM say 0xc7fffa10 and the RAM ends at 0xc8000000 then we have enough space to fit the data area (according to skb->len) but we would map beyond end of ram if we are using 2048. In v2.6.31 (against which kernel this patch made) there is the following check in dma_cache_maint(): |BUG_ON(!virt_addr_valid(start) || !virt_addr_valid(start + size - 1)); Since the area starting at 0xc8000000 is no longer virt_addr_valid() we BUG() during dma_map_single(). The BUG() statement was removed in v3.5-rc1 as per 2dc6a016 ("ARM: dma-mapping: use asm-generic/dma-mapping-common.h"). This patch was tested on v2.6.31 and then forward-ported and compile tested only against the net tree. I think it is still worth fixing mainline even after the BUG() statement is gone. Tested-by: Fugang Duan Cc: Marek Szyprowski Signed-off-by: Sebastian Andrzej Siewior Acked-by: Fugang Duan Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'drivers/net/ethernet/freescale/fec_main.c') diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 4cbebf3d80e..73b000df8a0 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -385,7 +385,7 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) * data. */ bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, bufaddr, - FEC_ENET_TX_FRSIZE, DMA_TO_DEVICE); + skb->len, DMA_TO_DEVICE); if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) { bdp->cbd_bufaddr = 0; fep->tx_skbuff[index] = NULL; @@ -779,11 +779,10 @@ fec_enet_tx(struct net_device *ndev) 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[index]; + dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr, skb->len, + DMA_TO_DEVICE); + bdp->cbd_bufaddr = 0; /* Check for errors. */ if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC | -- cgit v1.2.3-70-g09d2 From a1bf1750871a6f242b0fdb174cc55d2c57e7ed66 Mon Sep 17 00:00:00 2001 From: Philippe De Muyter Date: Wed, 11 Dec 2013 23:50:52 +0100 Subject: net:fec: remove duplicate lines in comment about errata ERR006358 commit 031916568a1aa2ef1809f86d26f0bcfa215ff5c0 worked around errata ERR006358, but comment contains duplicated lines, impairing the readability. Remove them. Signed-off-by: Philippe De Muyter Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'drivers/net/ethernet/freescale/fec_main.c') diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 73b000df8a0..e7c8b749c5a 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -98,10 +98,6 @@ static void set_multicast_list(struct net_device *ndev); * detected as not set during a prior frame transmission, then the * ENET_TDAR[TDAR] bit is cleared at a later time, even if additional TxBDs * were added to the ring and the ENET_TDAR[TDAR] bit is set. This results in - * If the ready bit in the transmit buffer descriptor (TxBD[R]) is previously - * detected as not set during a prior frame transmission, then the - * ENET_TDAR[TDAR] bit is cleared at a later time, even if additional TxBDs - * were added to the ring and the ENET_TDAR[TDAR] bit is set. This results in * frames not being transmitted until there is a 0-to-1 transition on * ENET_TDAR[TDAR]. */ -- cgit v1.2.3-70-g09d2 From 7a2a84518cfb263d2c4171b3d63671f88316adb2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 19 Dec 2013 10:53:02 -0800 Subject: net: fec: fix potential use after free skb_tx_timestamp(skb) should be called _before_ TX completion has a chance to trigger, otherwise it is too late and we access freed memory. Signed-off-by: Eric Dumazet Fixes: de5fb0a05348 ("net: fec: put tx to napi poll function to fix dead lock") Cc: Frank Li Cc: Richard Cochran Acked-by: Richard Cochran Acked-by: Frank Li Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/ethernet/freescale/fec_main.c') diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index e7c8b749c5a..50bb71c663e 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -428,6 +428,8 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) /* If this was the last BD in the ring, start at the beginning again. */ bdp = fec_enet_get_nextdesc(bdp, fep); + skb_tx_timestamp(skb); + fep->cur_tx = bdp; if (fep->cur_tx == fep->dirty_tx) @@ -436,8 +438,6 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) /* Trigger transmission start */ writel(0, fep->hwp + FEC_X_DES_ACTIVE); - skb_tx_timestamp(skb); - return NETDEV_TX_OK; } -- cgit v1.2.3-70-g09d2 From 7a399e3a2e05bc580a78ea72371b3896827f72e1 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Tue, 24 Dec 2013 12:16:01 -0200 Subject: fec: Do not assume that PHY reset is active low We should not assume that the PHY reset is always active low. Retrieve this information from the device tree instead, so that the PHY reset can work on both cases. Reported-by: Philipp Zabel Signed-off-by: Fabio Estevam Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec_main.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'drivers/net/ethernet/freescale/fec_main.c') diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 50bb71c663e..45b8b22b998 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -2049,6 +2049,8 @@ static void fec_reset_phy(struct platform_device *pdev) int err, phy_reset; int msec = 1; struct device_node *np = pdev->dev.of_node; + enum of_gpio_flags flags; + bool port; if (!np) return; @@ -2058,18 +2060,22 @@ static void fec_reset_phy(struct platform_device *pdev) if (msec > 1000) msec = 1; - phy_reset = of_get_named_gpio(np, "phy-reset-gpios", 0); + phy_reset = of_get_named_gpio_flags(np, "phy-reset-gpios", 0, &flags); if (!gpio_is_valid(phy_reset)) return; - err = devm_gpio_request_one(&pdev->dev, phy_reset, - GPIOF_OUT_INIT_LOW, "phy-reset"); + if (flags & OF_GPIO_ACTIVE_LOW) + port = GPIOF_OUT_INIT_LOW; + else + port = GPIOF_OUT_INIT_HIGH; + + err = devm_gpio_request_one(&pdev->dev, phy_reset, port, "phy-reset"); if (err) { dev_err(&pdev->dev, "failed to get phy-reset-gpios: %d\n", err); return; } msleep(msec); - gpio_set_value(phy_reset, 1); + gpio_set_value(phy_reset, !port); } #else /* CONFIG_OF */ static void fec_reset_phy(struct platform_device *pdev) -- cgit v1.2.3-70-g09d2