Fix several flaws in the error handling of the Siemens Gigaset ISDN driver,
including one that would cause an Oops when connecting more than one device
of the same type.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recently cpufreq support on my laptop (Lenovo T60) broke completely: when
it's plugged into AC it would never go higher than 1 GHz - neither 1.3 GHz
nor 1.83 GHz is possible - no matter which governor (userspace, speed or
ondemand) is used.

After some cpufreq debugging i tracked the regression back to the following
(totally correct) bug-fix commit:

   commit 0916bd3e
   Author: Dave Jones <davej@redhat.com>
   Date:   Wed Nov 22 20:42:01 2006 -0500

    [PATCH] Correct bound checking from the value returned from _PPC method.

This bugfix, which makes other laptops work, made a previously hidden
(BIOS) bug visible on my laptop.

The bug is the following: if the _PPC (Performance Present Capabilities)
optional ACPI object is queried /after/ bootup then the BIOS reports an
incorrect value of '2'.

My laptop (Lenovo T60) has the following performance states supported:

   0: 1833000
   1: 1333000
   2: 1000000

Per ACPI specification, a _PPC value of '0' means that all 3 performance
states are usable.  A _PPC value of '1' means states 1 ..  2 are usable, a
value of '2' means only state '2' (slowest) is usable.

now, the _PPC object is optional, and it also comes with notification.
Furthermore, when a CPU object is initialized, the _PPC object is
initialized as well.  So the following evaluation of the _PPC object is
superfluous:

 [<c028ba5f>] acpi_processor_get_platform_limit+0xa1/0xaf
 [<c028c040>] acpi_processor_register_performance+0x3b9/0x3ef
 [<c0111a85>] acpi_cpufreq_cpu_init+0xb7/0x596
 [<c03dab74>] cpufreq_add_dev+0x160/0x4a8
 [<c02bed90>] sysdev_driver_register+0x5a/0xa0
 [<c03d9c4c>] cpufreq_register_driver+0xb4/0x176
 [<c068ac08>] acpi_cpufreq_init+0xe5/0xeb
 [<c010056e>] init+0x14f/0x3dd

And this is the point where my laptop's BIOS returns the incorrect value of
'2'.  Note that it has not sent any notification event, so the value is
probably not really intentional (possibly spurious), and Windows likely
doesnt query it after bootup either.  Maybe the value is kept at '2'
normally, and is only set to the real value when a true asynchronous event
(such as AC plug event, battery switch, etc.) occurs.

So i /think/ this is a grey area of the ACPI spec: per the letter of the
spec the _PPC value only changes when notified, so there's no reason to
query it after the system has booted up.  So in my opinion the best (and
most compatible) strategy would be to do the change below, and to not
evaluate the _PPC object in the acpi_processor_get_performance_info() call,
but only evaluate it if _PPC is present during CPU object init, or if it's
notified during an asynchronous event.  This change is more permissive than
the previous logic, so it definitely shouldnt break any existing system.

This also happens to fix my laptop, which is merrily chugging along at
1.83 GHz now. Yay!
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@redhat.com>
Acked-by: NLen Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a SPI master device exists, udev (udevtrigger) causes kernel crash, due
to wrong kobj pointer in kobject_uevent_env().  This problem was not in
2.6.19.

The backtrace (on MIPS) was:
[<8024db6c>] kobject_uevent_env+0x54c/0x5e8
[<802a8264>] store_uevent+0x1c/0x3c  (in drivers/class.c)
[<801cb14c>] subsys_attr_store+0x2c/0x50
[<801cb80c>] flush_write_buffer+0x38/0x5c
[<801cb900>] sysfs_write_file+0xd0/0x190
[<80181444>] vfs_write+0xc4/0x1a0
[<80181cdc>] sys_write+0x54/0xa0
[<8010dae4>] stack_done+0x20/0x3c

flush_write_buffer() passes kobject of spi_master_class.subsys to
subsys_addr_store(), then subsys_addr_store() passes a pointer to a struct
subsystem to store_uevent() which expects a pointer to a struct
class_device.  The problem seems subsys_attr_store() called instead of
class_device_attr_store().

This mismatch was caused by commit
3bd0f694, which overrides kset of master
class.  This made spi_master_class.subsys.kset.ktype NULL so
subsys_sysfs_ops is used instead of class_dev_sysfs_ops.

The commit was to fix spi_busnum_to_master().  Here is a patch fixes
this function in other way, just searching children list of
class_device.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

/proc/*/mounstats was fixed, all right, but...

To reproduce:

	while true; do
		find /proc -type f 2>/dev/null | xargs cat 1>/dev/null 2>/dev/null;
	done

BUG: unable to handle kernel NULL pointer dereference at virtual address 0000000c
 printing eip:
c01754df
*pde = 00000000
Oops: 0000 [#28]
Modules linked in: af_packet ohci_hcd e1000 ehci_hcd uhci_hcd usbcore xfs
CPU:    0
EIP:    0060:[<c01754df>]    Not tainted VLI
EFLAGS: 00010286   (2.6.20-rc5 #1)
EIP is at mounts_open+0x1c/0xac
eax: 00000000   ebx: d5898ac0   ecx: d1d27b18   edx: d1d27a50
esi: e6083e10   edi: d3c87f38   ebp: d5898ac0   esp: d3c87ef0
ds: 007b   es: 007b   ss: 0068
Process cat (pid: 18071, ti=d3c86000 task=f7d5f070 task.ti=d3c86000)
Stack: d5898ac0 e6083e10 d3c87f38 c01754c3 c0147c91 c18c52c0 d343f314 d5898ac0
       00008000 d3c87f38 ffffff9c c0147e09 d5898ac0 00000000 00000000 c0147e4b
       00000000 d3c87f38 d343f314 c18c52c0 c015e53e 00001000 08051000 00000101
Call Trace:
 [<c01754c3>] mounts_open+0x0/0xac
 [<c0147c91>] __dentry_open+0xa1/0x18c
 [<c0147e09>] nameidata_to_filp+0x31/0x3a
 [<c0147e4b>] do_filp_open+0x39/0x40
 [<c015e53e>] seq_read+0x128/0x2aa
 [<c0147e8c>] do_sys_open+0x3a/0x6d
 [<c0147efa>] sys_open+0x1c/0x20
 [<c0102b76>] sysenter_past_esp+0x5f/0x85
 [<c02a0033>] unix_stream_recvmsg+0x3bf/0x4bf
 =======================
Code: 5d c3 89 d8 e8 06 e0 f9 ff eb bd 0f 0b eb fe 55 57 56 53 89 d5 8b 40 f0 31 d2 e8 02 c1 fa ff 89 c2 85 c0 74 5c 8b 80 48 04 00 00 <8b> 58 0c 85 db 74 02 ff 03 ff 4a 08 0f 94 c0 84 c0 75 74 85 db
EIP: [<c01754df>] mounts_open+0x1c/0xac SS:ESP 0068:d3c87ef0

A race with do_exit()'s call to exit_namespaces().
Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes x86_64 define arch_vma_name for CONFIG_IA32_EMULATION.  This
makes the ia32 vDSO mapping appear in /proc/PID/maps with "[vdso]" for ia32
processes, as it does on native i386.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes core dumps to include the vDSO vma, which is left out now.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes ia32 core dumps on x86_64 to include just one phdr for the
vDSO vma.  Currently it writes a confused format with two phdrs for the
address, one without contents and one with.  This patch removes the
special-case core writing macros for the ia32 vDSO.  Instead, it uses
VM_ALWAYSDUMP in the vma.  This changes core dumps so they no longer include
the non-PT_LOAD phdrs from the vDSO, consistent with fixed native i386 core
dumps.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes core dumps to include the vDSO vma, which is left out now.
It removes the special-case core writing macros, which were not doing the
right thing for the vDSO vma anyway.  Instead, it uses VM_ALWAYSDUMP in the
vma; there is no need for the fixmap page to be installed.  It handles the
CONFIG_COMPAT_VDSO case by making elf_core_dump use the fake vma from
get_gate_vma after real vmas in the same way the /proc/PID/maps code does.

This changes core dumps so they no longer include the non-PT_LOAD phdrs from
the vDSO.  I made the change to add them in the first place, but in turned out
that nothing ever wanted them there since the advent of NT_AUXV.  It's cleaner
to leave them out, and just let the phdrs inside the vDSO image speak for
themselves.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds the VM_ALWAYSDUMP flag for vm_flags in vm_area_struct.  This
provides a clean explicit way to have a vma always included in core dumps, as
is needed for vDSO's.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes the initialization of gate_vma.vm_flags and
gate_vma.vm_page_prot to reflect reality.  This makes the "[vdso]" line in
/proc/PID/maps correctly show r-xp instead of ---p, when gate_vma is used
(CONFIG_COMPAT_VDSO on i386).
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I wouldn't mind if CONFIG_COMPAT_VDSO went away entirely.  But if it's there,
it should work properly.  Currently it's quite haphazard: both real vma and
fixmap are mapped, both are put in the two different AT_* slots, sysenter
returns to the vma address rather than the fixmap address, and core dumps yet
are another story.

This patch makes CONFIG_COMPAT_VDSO disable the real vma and use the fixmap
area consistently.  This makes it actually compatible with what the old vdso
implementation did.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently the spi mode can be set to the wrong mode if you are switching
from any mode other than mode 0.  This is because the mode is set using a
bitwise or on uncleared bits.  The following patch clears the mode bits
before setting the new mode.  I've also modified it to use the appropriate
defines from pxa-regs.h for readability.
Signed-off-by: NJustin Clacherty <justin@redfish-group.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It turns out that the spi chipselect was not being passed to the set_cs
routine if one was specified in the platform data.

As part of the fix, change to using a set_cs field in the controller state,
and put a default gpio routine in if the data passed does not specify it.

Also remove the //#define DEBUG
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements forwarding of SHUTDOWN intercepts from the guest on to
userspace on AMD SVM.  A SHUTDOWN event occurs when the guest produces a
triple fault (e.g.  on reboot).  This also fixes the bug that a guest reboot
actually causes a host reboot under some circumstances.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the recent guest page fault change, we perform access checks on our
own instead of relying on the cpu.  This means we have to perform the nx
checks as well.

Software like the google toolbar on windows appears to rely on this
somehow.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Check pte permission bits in walk_addr(), instead of scattering the checks all
over the code.  This has the following benefits:

1. We no longer set the accessed bit for accessed which fail permission checks.
2. Setting the accessed bit is simplified.
3. Under some circumstances, we used to pretend a page fault was fixed when
   it would actually fail the access checks.  This caused an unnecessary
   vmexit.
4. The error code for guest page faults is now correct.

The fix helps netbsd further along booting, and allows kvm to pass the new mmu
testsuite.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allows netbsd 3.1 i386 to get further along installing.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's an obvious typo in svm_{get,set}_idt, causing it to access the ldt
instead.

Because these functions are only called for save/load on AMD, the bug does not
impact normal operation.  With the fix, save/load works as expected on AMD
hosts.
Signed-off-by: NUri Lublin <uril@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In __writeback_single_inode(), when we find a locked inode and we're not
doing a data-integrity sync, we used to just skip writing entirely,
since we didn't want to wait for the inode to unlock.

However, there's really no reason to skip writing the data pages, which
are likely to be the the bulk of the dirty state anyway (and the main
reason why writeback was started for the non-data-integrity case, of
course!)
Acked-by: NNick Piggin <nickpiggin@yahoo.com.au>
Cc: Andrew Morton <akpm@osdl.org>,
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It's not pretty, but it appears that ext3 with data=journal will clean
pages without ever actually telling the VM that they are clean.  This,
in turn, will result in the VM (and balance_dirty_pages() in particular)
to never realize that the pages got cleaned, and wait forever for an
event that already happened.

Technically, this seems to be a problem with ext3 itself, but it used to
be hidden by 'try_to_free_buffers()' noticing this situation on its own,
and just working around the filesystem problem.

This commit re-instates that hack, in order to avoid a regression for
the 2.6.20 release. This fixes bugzilla 7844:

	http://bugzilla.kernel.org/show_bug.cgi?id=7844

Peter Zijlstra points out that we should probably retain the debugging
code that this removes from cancel_dirty_page(), and I agree, but for
the imminent release we might as well just silence the warning too
(since it's not a new bug: anything that triggers that warning has been
around forever).
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NJens Axboe <jens.axboe@oracle.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On x86-64, a put_user call using a 64-bit pointer and a constant value that
is > 0xffffffff will produce code that doesn't assemble.  This patch fixes
the asm construct to use the Z constraint for 32-bit constants.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Fix wrong checksum calculation on 64-bit MIPS
  [MIPS] VPE loader: Initialize lists before they're actually being used ...
  [MIPS] Fix reported amount of freed memory - it's in kB not bytes
  [MIPS] vr41xx: need one more nop with mtc0_tlbw_hazard()
  [MIPS] SMTC: Fix module build by exporting symbol
  [MIPS] SMTC: Fix TLB sizing bug for TLB of 64 >= entries
  [MIPS] Fix APM build
  [MIPS] There is no __GNUC_MAJOR__

Prevent the call to invalidate_inode_pages2() from racing with file writes
by taking the inode->i_mutex across the page cache flush and invalidate.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the Oops in http://bugzilla.linux-nfs.org/show_bug.cgi?id=138
We shouldn't be calling rpc_release_task() for tasks that are not active.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The commit 8e3d8433 ([NET]: MIPS
checksum annotations and cleanups) broke 64-bit MIPS.

The problem is the commit replaces some unsigned long with __be32.  On
64bit MIPS, a __be32 (i.e. unsigned int) value is represented as a
sign-extented 32-bit value in a 64-bit argument register.  So the
address 192.168.0.1 (0xc0a80001) is passed as 0xffffffffc0a80001 to
csum_tcpudp_nofold() but the asm code in the function expects
0x00000000c0a80001, therefore it returns a wrong checksum.  Explicit
cast to unsigned long is needed to drop high 32bit.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

kspd which due to makefile order happens to be initialized before the
vpe loader causes references to vpecontrol lists before they're actually
been initialized.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

While at it, change message on DEC for consistency.
Signed-off-by: NThiemo Seufer <ths@networkno.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

NEC VR4111 and VR4121 need one more nop with mtc0_tlbw_hazard().
Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Definitions for TIF_FREEZE and _TIF_FREEZE were missing.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Gcc major version number is in __GNUC__. As side effect fix checking
with sparse if sparse was built with gcc 4.1 and mips cross-compiler
is 3.4.

Sparse will inherit version 4.1, __GNUC__ won't be filtered from
"-dM -E -xc" output, sparse will pick only new major, effectively becoming
gcc version 3.1 which is unsupported.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [CIFS] Fix oops when Windows server sent bad domain name null terminator
  [CIFS]  cifs sprintf fix
  [CIFS] Remove 2 unneeded kzalloc casts
  [CIFS] Update CIFS version number

* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (23 commits)
  [SCTP]: Fix compiler warning.
  [IP] TUNNEL: Fix to be built with user application.
  [IPV6]: Fixed the size of the netlink message notified by inet6_rt_notify().
  [TCP]: rare bad TCP checksum with 2.6.19
  [NET]: Process include/linux/if_{addr,link}.h with unifdef
  [NETFILTER]: Fix iptables ABI breakage on (at least) CRIS
  [IRDA] vlsi_ir.{h,c}: remove kernel 2.4 code
  [TCP]: skb is unexpectedly freed.
  [IPSEC]: Policy list disorder
  [IrDA]: Removed incorrect IRDA_ASSERT()
  [IrDA]: irda-usb TX path optimization (was Re: IrDA spams logfiles - since 2.6.19)
  [X.25]: Add missing sock_put in x25_receive_data
  [SCTP]: Fix SACK sequence during shutdown
  [SCTP]: Correctly handle unexpected INIT-ACK chunk.
  [SCTP]: Verify some mandatory parameters.
  [SCTP]: Set correct error cause value for missing parameters
  [NETFILTER]: fix xt_state compile failure
  [NETFILTER]: ctnetlink: fix leak in ctnetlink_create_conntrack error path
  [SELINUX]: increment flow cache genid
  [IPV6] MCAST: Fix joining all-node multicast group on device initialization.
  ...

* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6:
  mv643xx_eth: Fix race condition in mv643xx_eth_free_tx_descs
  s2io bogus memset

Initialize qc->pad_len for each new command. This ensures
that pad_len is not set to a stale value for zero data
length commands.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Fixup the inialization of qc->n_elem. It currently gets
initialized to 1 for commands that do not transfer any data.
Fix this by initializing n_elem to 0 and only setting to 1
in ata_scsi_qc_new when there is data to transfer. This fixes
some problems seen with SATA devices attached to ipr adapters.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some ATA/ATAPI devices act weirdly after the link is put into slumber
mode.  Some hang completely requiring physical power removal while
others fail to wake up till the link is hardreset a couple of times.

The addition of slumber on power down was never driven by real need.
It just followed what ahci spec said literally.  The spec itself seems
faulty in that it doesn't consider devices (not controllers) which
don't support link powersaving mode.

Theory never matches reality when it comes to dark allys of cheap
ATA/ATAPI world.  It's just unrealistic to expect vendors to test
rarely used link powersaving feature rigorously.  This patch makes
ahci more friendly to the coldness of reality.

This shouldn't have any negative effect - when suspend operation
succeeds, we power off the whole machine; otherwise, we wake up
everything.  I can't see any reason to be so elaborate with powering
down the link in the first place.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>