ChangeSet 1.1420, 2003/11/07 10:19:35-08:00, david-b@pacbell.net
[PATCH] USB: usb ignores 64bit dma
The dma hooks whereby EHCI can pass 64bit DMA support
up the driver stack (to avoid buffer copies) turn out
to broken on most architectures(*). This patch just
disables them all, since it looks like those mechanisms
won't get fixed before 2.6.0-final. For now it'd only
matter on a few big Intel boxes anyway.
Please merge.
- Dave
(*) On x86, mips, and arm dma_supported() doesn't
even compare with the device's mask. On several
other architectures (reported on ppc, alpha,
and sparc64), asking that question for non-PCI
devices will just BUG() -- even though all info
needed to answer the question is right at hand.
drivers/usb/host/ehci-hcd.c | 3 +++
drivers/usb/net/kaweth.c | 3 +++
drivers/usb/net/usbnet.c | 3 +++
3 files changed, 9 insertions(+)
diff -Nru a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
--- a/drivers/usb/host/ehci-hcd.c Fri Nov 7 11:22:04 2003
+++ b/drivers/usb/host/ehci-hcd.c Fri Nov 7 11:22:04 2003
@@ -426,8 +426,11 @@
*/
if (HCC_64BIT_ADDR (hcc_params)) {
writel (0, &ehci->regs->segment);
+#if 0
+// this is deeply broken on almost all architectures
if (!pci_set_dma_mask (ehci->hcd.pdev, 0xffffffffffffffffULL))
ehci_info (ehci, "enabled 64bit PCI DMA\n");
+#endif
}
/* help hc dma work well with cachelines */
diff -Nru a/drivers/usb/net/kaweth.c b/drivers/usb/net/kaweth.c
--- a/drivers/usb/net/kaweth.c Fri Nov 7 11:22:04 2003
+++ b/drivers/usb/net/kaweth.c Fri Nov 7 11:22:04 2003
@@ -1120,8 +1120,11 @@
usb_set_intfdata(intf, kaweth);
+#if 0
+// dma_supported() is deeply broken on almost all architectures
if (dma_supported (&intf->dev, 0xffffffffffffffffULL))
kaweth->net->features |= NETIF_F_HIGHDMA;
+#endif
SET_NETDEV_DEV(netdev, &intf->dev);
if (register_netdev(netdev) != 0) {
diff -Nru a/drivers/usb/net/usbnet.c b/drivers/usb/net/usbnet.c
--- a/drivers/usb/net/usbnet.c Fri Nov 7 11:22:04 2003
+++ b/drivers/usb/net/usbnet.c Fri Nov 7 11:22:04 2003
@@ -2972,9 +2972,12 @@
strcpy (net->name, "usb%d");
memcpy (net->dev_addr, node_id, sizeof node_id);
+#if 0
+// dma_supported() is deeply broken on almost all architectures
// possible with some EHCI controllers
if (dma_supported (&udev->dev, 0xffffffffffffffffULL))
net->features |= NETIF_F_HIGHDMA;
+#endif
net->change_mtu = usbnet_change_mtu;
net->get_stats = usbnet_get_stats;