]> git.baikalelectronics.ru Git - kernel.git/commit
Revert "xhci 1.0: Limit arbitrarily-aligned scatter gather."
authorMathias Nyman <mathias.nyman@linux.intel.com>
Fri, 7 Mar 2014 15:06:57 +0000 (17:06 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 7 Mar 2014 19:48:13 +0000 (11:48 -0800)
commita7c070d8b93e9c2c63103b90d8744f67d25bccfb
treef39f2ab4e1a24843cd95144344111f7ec52af2ee
parentd696837cd59f566b6ab463eafcd9534bdcaff376
Revert "xhci 1.0: Limit arbitrarily-aligned scatter gather."

This reverts commit 21a7c3dfabc2334e9f4d7a1665e6fbb4d215e31e.

This commit, together with commit 9912f321f625e5daca91292c566d4c698865508b
"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>
drivers/usb/host/xhci.c