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27 March 2024, 02:37:15 UTC
Revision 85746e429f8e5dc8c5c0beadc0f099cb1feab93e authored by Linus Torvalds on 07 July 2011, 20:16:21 UTC, committed by Linus Torvalds on 07 July 2011, 20:16:21 UTC 
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
 
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (31 commits)
  sctp: fix missing send up SCTP_SENDER_DRY_EVENT when subscribe it
  net: refine {udp|tcp|sctp}_mem limits
  vmxnet3: round down # of queues to power of two
  net: sh_eth: fix the parameter for the ETHER of SH7757
  net: sh_eth: fix cannot work half-duplex mode
  net: vlan: enable soft features regardless of underlying device
  vmxnet3: fix starving rx ring whenoc_skb kb fails
  bridge: Always flood broadcast packets
  greth: greth_set_mac_add would corrupt the MAC address.
  net: bind() fix error return on wrong address family
  natsemi: silence dma-debug warnings
  net: 8139too: Initial necessary vlan_features to support vlan
  Fix call trace when interrupts are disabled while sleeping function kzalloc is called
  qlge:Version change to v1.00.00.29
  qlge: Fix printk priority so chip fatal errors are always reported.
  qlge:Fix crash caused by mailbox execution on wedged chip.
  xfrm4: Don't call icmp_send on local error
  ipv4: Don't use ufo handling on later transformed packets
  xfrm: Remove family arg from xfrm_bundle_ok
  ipv6: Don't put artificial limit on routing table size.
  ...
2 parent s 4dd1b49 + 9491230
Raw File
Tip revision: 85746e429f8e5dc8c5c0beadc0f099cb1feab93e authored by Linus Torvalds on 07 July 2011, 20:16:21 UTC
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
Tip revision: 85746e4
usb-legacy-support.txt 
USB Legacy support
~~~~~~~~~~~~~~~~~~

Vojtech Pavlik <vojtech@suse.cz>, January 2004


Also known as "USB Keyboard" or "USB Mouse support" in the BIOS Setup is a
feature that allows one to use the USB mouse and keyboard as if they were
their classic PS/2 counterparts.  This means one can use an USB keyboard to
type in LILO for example.

It has several drawbacks, though:

1) On some machines, the emulated PS/2 mouse takes over even when no USB
   mouse is present and a real PS/2 mouse is present.  In that case the extra
   features (wheel, extra buttons, touchpad mode) of the real PS/2 mouse may
   not be available.

2) If CONFIG_HIGHMEM64G is enabled, the PS/2 mouse emulation can cause
   system crashes, because the SMM BIOS is not expecting to be in PAE mode.
   The Intel E7505 is a typical machine where this happens.

3) If AMD64 64-bit mode is enabled, again system crashes often happen,
   because the SMM BIOS isn't expecting the CPU to be in 64-bit mode.  The
   BIOS manufacturers only test with Windows, and Windows doesn't do 64-bit
   yet.

Solutions:

Problem 1) can be solved by loading the USB drivers prior to loading the
PS/2 mouse driver. Since the PS/2 mouse driver is in 2.6 compiled into
the kernel unconditionally, this means the USB drivers need to be
compiled-in, too.

Problem 2) can currently only be solved by either disabling HIGHMEM64G
in the kernel config or USB Legacy support in the BIOS. A BIOS update
could help, but so far no such update exists.

Problem 3) is usually fixed by a BIOS update. Check the board
manufacturers web site. If an update is not available, disable USB
Legacy support in the BIOS. If this alone doesn't help, try also adding
idle=poll on the kernel command line. The BIOS may be entering the SMM
on the HLT instruction as well.
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