diff options
| author | Robert Hancock <hancockrwd@gmail.com> | 2010-02-19 17:10:15 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-02-19 17:10:15 -0800 |
| commit | 353176888386d9025062a12dcec08d49af10cf2c (patch) | |
| tree | 75ebc4c4a910f8187e784d75abf5f4be159011f7 /drivers/net/r8169.c | |
| parent | e4fc85600b1b4b8114354846ab9594ad354882d0 (diff) | |
r8169: enable 64-bit DMA by default for PCI Express devices (v2)
Currently use of 64-bit DMA is disabled in r8169 unless the user passes the
use_dac module option. This is reasonable for conventional PCI devices where
broken chipsets may not handle dual-address-cycle transfers properly for
32-bit slots and so this may not be safe. However, PCI Express should not have
this problem and not using 64-bit DMA results in DMA transfers needlessly using
the IOMMU or SWIOTLB. Set the use_dac module parameter to a new default value of
-1 which results in 64-bit DMA being enabled by default for PCI Express devices
only.
Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/r8169.c')
| -rw-r--r-- | drivers/net/r8169.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c index 616ae5aa66aa..83965eeba456 100644 --- a/drivers/net/r8169.c +++ b/drivers/net/r8169.c @@ -187,7 +187,7 @@ static DEFINE_PCI_DEVICE_TABLE(rtl8169_pci_tbl) = { MODULE_DEVICE_TABLE(pci, rtl8169_pci_tbl); static int rx_copybreak = 200; -static int use_dac; +static int use_dac = -1; static struct { u32 msg_enable; } debug = { -1 }; @@ -511,7 +511,8 @@ MODULE_DESCRIPTION("RealTek RTL-8169 Gigabit Ethernet driver"); module_param(rx_copybreak, int, 0); MODULE_PARM_DESC(rx_copybreak, "Copy breakpoint for copy-only-tiny-frames"); module_param(use_dac, int, 0); -MODULE_PARM_DESC(use_dac, "Enable PCI DAC. Unsafe on 32 bit PCI slot."); +MODULE_PARM_DESC(use_dac, "Enable PCI DAC. -1 defaults on for PCI Express only." +" Unsafe on 32 bit PCI slot."); module_param_named(debug, debug.msg_enable, int, 0); MODULE_PARM_DESC(debug, "Debug verbosity level (0=none, ..., 16=all)"); MODULE_LICENSE("GPL"); @@ -2973,6 +2974,7 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) void __iomem *ioaddr; unsigned int i; int rc; + int this_use_dac = use_dac; if (netif_msg_drv(&debug)) { printk(KERN_INFO "%s Gigabit Ethernet driver %s loaded\n", @@ -3038,8 +3040,17 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) tp->cp_cmd = PCIMulRW | RxChkSum; + tp->pcie_cap = pci_find_capability(pdev, PCI_CAP_ID_EXP); + if (!tp->pcie_cap) + netif_info(tp, probe, dev, "no PCI Express capability\n"); + + if (this_use_dac < 0) + this_use_dac = tp->pcie_cap != 0; + if ((sizeof(dma_addr_t) > 4) && - !pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) && use_dac) { + this_use_dac && + !pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) { + netif_info(tp, probe, dev, "using 64-bit DMA\n"); tp->cp_cmd |= PCIDAC; dev->features |= NETIF_F_HIGHDMA; } else { @@ -3058,10 +3069,6 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) goto err_out_free_res_4; } - tp->pcie_cap = pci_find_capability(pdev, PCI_CAP_ID_EXP); - if (!tp->pcie_cap) - netif_info(tp, probe, dev, "no PCI Express capability\n"); - RTL_W16(IntrMask, 0x0000); /* Soft reset the chip. */ |