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authorMathias Nyman <mathias.nyman@linux.intel.com>2014-03-07 17:06:57 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-03-07 11:48:13 -0800
commite2ed511400d41e0d136089d5a55ceab57c6a2426 (patch)
treef39f2ab4e1a24843cd95144344111f7ec52af2ee
parentd86db25e53fa69e3e97f3b55dd82a70689787c5d (diff)
downloadlinux-e2ed511400d41e0d136089d5a55ceab57c6a2426.tar.gz
Revert "xhci 1.0: Limit arbitrarily-aligned scatter gather."
This reverts commit 247bf557273dd775505fb9240d2d152f4f20d304. This commit, together with commit 3804fad45411b48233b48003e33a78f290d227c8 "USBNET: ax88179_178a: enable tso if usb host supports sg dma" were origially added to get xHCI 1.0 hosts and usb ethernet ax88179_178a devices working together with scatter gather. xHCI 1.0 hosts pose some requirement on how transfer buffers are aligned, setting this requirement for 1.0 hosts caused USB 3.0 mass storage devices to fail more frequently. USB 3.0 mass storage devices used to work before 3.14-rc1. Theoretically, the TD fragment rules could have caused an occasional disk glitch. Now the devices *will* fail, instead of theoretically failing. >From a user perspective, this looks like a regression; the USB device obviously fails on 3.14-rc1, and may sometimes silently fail on prior kernels. The proper soluition is to implement the TD fragment rules required, but for now this patch needs to be reverted to get USB 3.0 mass storage devices working at the level they used to. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/host/xhci.c14
1 files changed, 3 insertions, 11 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6fe577d46fa2..924a6ccdb622 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4733,6 +4733,9 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
/* Accept arbitrarily long scatter-gather lists */
hcd->self.sg_tablesize = ~0;
+ /* support to build packet from discontinuous buffers */
+ hcd->self.no_sg_constraint = 1;
+
/* XHCI controllers don't stop the ep queue on short packets :| */
hcd->self.no_stop_on_short = 1;
@@ -4757,14 +4760,6 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
/* xHCI private pointer was set in xhci_pci_probe for the second
* registered roothub.
*/
- xhci = hcd_to_xhci(hcd);
- /*
- * Support arbitrarily aligned sg-list entries on hosts without
- * TD fragment rules (which are currently unsupported).
- */
- if (xhci->hci_version < 0x100)
- hcd->self.no_sg_constraint = 1;
-
return 0;
}
@@ -4793,9 +4788,6 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
if (xhci->hci_version > 0x96)
xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
- if (xhci->hci_version < 0x100)
- hcd->self.no_sg_constraint = 1;
-
/* Make sure the HC is halted. */
retval = xhci_halt(xhci);
if (retval)