The current LPM implementation has the following issues.
* Operation order isn't well thought-out. e.g. HIPM should be
configured after IPM in SControl is properly configured. Not the
other way around.
* Suspend/resume paths call ata_lpm_enable/disable() which must only
be called from EH context directly. Also, ata_lpm_enable/disable()
were called whether LPM was in use or not.
* Implementation is per-port when it should be per-link. As a result,
it can't be used for controllers with slave links or PMP.
* LPM state isn't managed consistently. After a link reset for
whatever reason including suspend/resume the actual LPM state would
be reset leaving ap->lpm_policy inconsistent.
* Generic/driver-specific logic boundary isn't clear. Currently,
libahci has to mangle stuff which libata EH proper should be
handling. This makes the implementation unnecessarily complex and
fragile.
* Tied to ALPM. Doesn't consider DIPM only cases and doesn't check
whether the device allows HIPM.
* Error handling isn't implemented.
Given the extent of mismatch with the rest of libata, I don't think
trying to fix it piecewise makes much sense. This patch reimplements
LPM support.
* The new implementation is per-link. The target policy is still
port-wide (ap->target_lpm_policy) but all the mechanisms and states
are per-link and integrate well with the rest of link abstraction
and can work with slave and PMP links.
* Core EH has proper control of LPM state. LPM state is reconfigured
when and only when reconfiguration is necessary. It makes sure that
LPM state is reset when probing for new device on the link.
Controller agnostic logic is now implemented in libata EH proper and
driver implementation only has to deal with controller specifics.
* Proper error handling. LPM config failure is attributed to the
device on the link and LPM is disabled for the link if it fails
repeatedly.
* ops->enable/disable_pm() are replaced with single ops->set_lpm()
which takes @policy and @hints. This simplifies driver specific
implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Link power management related symbols are in confusing state w/ mixed
usages of lpm, ipm and pm. This patch cleans up lpm related symbols
and sysfs show/store functions as follows.
* lpm states - NOT_AVAILABLE, MIN_POWER, MAX_PERFORMANCE and
MEDIUM_POWER are renamed to ATA_LPM_UNKNOWN and
ATA_LPM_{MIN|MAX|MED}_POWER.
* Pre/postfixes are unified to lpm.
* sysfs show/store functions for link_power_management_policy were
curiously named get/put and unnecessarily complex. Renamed to
show/store and simplified.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata depends on scsi_host_template for module reference counting and
sht's should be owned by each low level driver. During libahci split,
the sht was left with libahci.ko leaving the actual low level drivers
not reference counted. This made ahci and ahci_platform always
unloadable even while they're being actively used.
Fix it by defining AHCI_SHT() macro in ahci.h and defining a sht for
each low level ahci driver.
stable: only applicable to 2.6.35.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Pedro Francisco <pedrogfrancisco@gmail.com>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch adds the Intel Patsburg (PCH) SATA AHCI and RAID Controller
DeviceIDs.
Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
88SE9128 can do FBS and sets it in HOST_CAP but forgets to set FBSCP
in PORT_CMD. Implement AHCI_HFLAG_YES_FBS and apply it to 88SE9128.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The below patch casts ATA_MAX_QUEUE to int because GCC will
give a warning message about the two different enum blocks:
CC drivers/ata/ahci.o
drivers/ata/ahci.c: In function 'ahci_init_one':
drivers/ata/ahci.c:1045:2: warning: comparison between 'enum <anonymous>' and 'enum <anonymous>'
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
For yet unknown reason, MCP89 on MBP 7,1 doesn't work w/ ahci under
linux but the controller doesn't require explicit mode setting and
works fine with ata_generic. Make ahci ignore the controller on MBP
7,1 and let ata_generic take it for now.
Reported in bko#15923.
https://bugzilla.kernel.org/show_bug.cgi?id=15923
NVIDIA is investigating why ahci mode doesn't work.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Cc: stable@kernel.org
Reported-by: Anders Østhus <grapz666@gmail.com>
Reported-by: Andreas Graf <andreas_graf@csgraf.de>
Reported-by: Benoit Gschwind <gschwind@gnu-log.net>
Reported-by: Damien Cassou <damien.cassou@gmail.com>
Reported-by: tixetsal@juno.com
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Detect enclosure management message type automatically at driver
initialization, instead of using module parameter "ahci_em_messages".
Signed-off-by: Harry Zhang <harry.zhang@amd.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
It turns out different generations of MCPs have differing quirks.
* MCP 65-73 : FPDMA AA broken, lies about PMP support, forgets to report NCQ
* MCP 77-79 : FPDMA AA broken, lies about PMP support
* MCP 89 : FPDMA AA broken
Instead of turngin off FPDMA AA on all NVIDIAs, implement
HFLAG_NO_FPDMA_AA, define additional board IDs and apply necessary
quirks.
This fixes bko#15481 and the list of quirks is verified by Peer Chen.
http://bugzilla.kernel.org/show_bug.cgi?id=15481
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
ahci over time has grown a number of board IDs and it's a bit of mess
right now. Clean it up such that,
* board_id_* now live in a separate enum board_ids and numbers are
assigned automatically.
* Board IDs assigned to features are separated from the ones assigned
to specific implementations and both are ordered alphabetically.
* For NV MCPs, define per-generation alias board_ids and assign
matching aliases in the pci id table. This makes mcp_linux, 67-73
use board_ahci_mcp65 instead of board_ahci_yesncq. Both are
identical in content.
* Kill now unused board_ahci_nopmp and board_ahci_yesncq.
This patch doesn't cause any functional change but will make future
changes to board_ids and quirks much less painful.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch should contain no functional changes, just moves code
around.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Factor out some ahci_em_messages handling code from ahci_init_one().
We would like to reuse it for non-PCI devices.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Introduce ahci_pci_print_info() that now handles PCI stuff.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Move PCI stuff into ahci_pci_init_controller().
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
To make the function bus-independand we have to get rid of
"struct pci_dev *", so let's pass just "struct devce *".
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Move PCI stuff into ahci_pci_reset_controller().
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
To make the function generic we have to get rid of "struct pci_dev *",
so let's pass just a "struct devce *".
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Make ahci_save_initial_config() a bit more generic by introducing
force_port_map and mask_port_map arguments.
Move PCI stuff into ahci_pci_save_initial_config().
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Currently the driver uses host->iomap to store all the iomapped BARs
of a PCI device (while AHCI devices actually use just a single memory
window).
We're going to teach AHCI to work with non-PCI buses, so there are two
options to make this work:
1. "fake" host->iomap array for non-PCI devices, and place the needed
address at iomap[AHCI_PCI_BAR];
2. Get rid of host->iomap usage, instead introduce a private mmio
field.
This patch implements the second option.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
pp->active_link is not reliable when FBS is enabled.
Both PORT_SCR_ACT and PORT_CMD_ISSUE should be checked
because mixed NCQ and non-NCQ commands may be in flight.
Signed-off-by: Shane Huang <shane.huang@amd.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
HP is recycling both DMI_PRODUCT_NAME and DMI_BIOS_VERSION making
ahci_broken_suspend() trigger for later products which are not
affected by the original problems. Match BIOS date instead of version
and add references to bko's so that full information can be found
easier later.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=15462
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: tigerfishdaisy@gmail.com
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
bko#15481 shows that we're missing some NVIDIA ahci PCI IDs. Peer
Chen confirms that IDs 0x580-0x58f are reserved for cases where Linux
ID option is selected in the BIOS and are only used for mcp65-73. Add
0x0581-0x058f.
http://bugzilla.kernel.org/show_bug.cgi?id=15481
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Make some variables in ahci and a function in pata_pcmcia static, as found
using sparse.
Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mike Cui reported that his system with an NVIDIA MCP79 (aka MCP7A)
chipset stopped working with 2.6.32. The problem appears to be that
2.6.32 now enables the FPDMA auto-activate optimization in the ahci
driver. The drive works fine with this enabled on an Intel AHCI so
this appears to be a chipset bug. Since MCP79 is a fairly recent
NVIDIA chipset and we don't have any info on whether any other NVIDIA
chipsets have this issue, disable FPDMA AA optimization on all NVIDIA
AHCI controllers for now.
Should address http://bugzilla.kernel.org/show_bug.cgi?id=14922
Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
While-we-investigate-issue-this-patch-looks-good-to-me-by:
Prajakta Gudadhe <pgudadhe@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: stable@kernel.org
Acer G725 shares the same suspend problem with the HP laptops which
lose ATA devices on resume. New firmware which fixes the problem is
already available. Add G725 with old firmwares to the broken suspend
list.
This problem has been reported in bko#15104.
http://bugzilla.kernel.org/show_bug.cgi?id=15104
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jani-Matti Hätinen <jani-matti.hatinen@iki.fi>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
ahci can drive the Promise PDC42819, but obviously it can only use SATA
disks connected to this controller. The controller can actually support
SAS disks as well, but we only know how to use it in it's AHCI mode.
Add a message to let users know that because ahci is driving their chip
they can only use the SATA disks connected to this controller.
Signed-off-by: Mark Nelson <mdnelson8@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
I obseved there is a sata_async_notification() for every ahci
interrupt. But the async notification does nothing (this is hard
disk drive and no pmp). This cause cpu wastes some time on sntf
register access.
It appears ICH AHCI doesn't support SNotification register, but the
controller reports it does. After quirking it, the async notification
disappears.
PS. it appears all ICH don't support SNotification register from ICH
manual, don't know if we need quirk all ICH. I don't have machines
with all kinds of ICH.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Like the Asus M2A-VM, MSI's K9A2 Platinum (MS-7376) can also support 64bit
DMA. It is a new enough board that all the BIOS releases work correctly with
64bit DMA enabled.
Signed-off-by: Mark Nelson <mdnelson8@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Commit f80ae7e45a
ahci: filter FPDMA non-zero offset enable for Aspire 3810T
breaks the current git build for configurations that don't define
CONFIG_ATA_ACPI.
This adds an ifdef wrapper to ahci_gtf_filter_workaround.
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Curiously, Aspire 3810T issues many SATA feature enable commands via
_GTF, of which one is invalid and another is not supported by the
drive. In the process, it also enables FPDMA non-zero offset.
However, the feature also needs to be supported and enabled from the
controller and it's wrong to enable it from _GTF unless the controller
can do it by default.
Currently, this ends up enabling FPDMA non-zero offset only on the
drive side leading to NCQ command failures and eventual disabling of
NCQ. This patch makes libata filter out FPDMA non-zero offset enable
for the machine.
This was reported by Marcus Meissner in bnc#522790.
https://bugzilla.novell.com/show_bug.cgi?id=522790
Reported-by: Marcus Meissner <meissner@novell.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Update the AHCI driver to display all of the HBA capabilities defined in the
AHCI 1.3 specification. Some of these are in a new CAP2 (HBA Capabilities
Extended) register which is only defined on AHCI 1.2 or later. The spec says
that undefined registers should always return 0 on read, but to be safe we
assume a value of 0 unless the controller reports AHCI version 1.2 or later.
The value can also be retrieved through sysfs as with the existing capability
field.
For example, on an Intel Ibex Peak (PCH) controller:
ahci 0000:00:1f.2: flags: 64bit ncq sntf stag pm led clo pmp pio slum part ems
sxs apst
We don't do anything special with the new flags yet.
Also, change the code that displays the flags to use the same bit enumerations
that are used to control actual operation.
Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Till now only one board, ASUS M2A-VM, can do 64bit dma with recent
BIOSen. Enabling 64bit DMA by default already broke three boards.
Enabling 64bit DMA isn't worth these regressions. Disable 64bit DMA
by default and enable it only on boards which are known to work.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Gabriele Balducci <balducci@units.it>
Reported-by: maierp@informatik.tu-muenchen.de
Cc: Shane Huang <shane.huang@amd.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Commit a5bfc4714b dropped explicit
pci_intx() manipulation from ahci because it seemed unnecessary and
ahci doesn't seem to be the right place to be tweaking it if it were.
This was largely okay but there are exceptions. There was one on an
embedded platform which was fixed via firmware and now bko#14124
reports it on a HP DL320.
http://bugzilla.kernel.org/show_bug.cgi?id=14124
I still think this isn't something libata drivers should be caring
about (the only ones which are calling pci_intx() explicitly are
libata ones and one other driver) but for now reverting the change
seems to be the right thing to do.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This patch refines ahci_kick_engine() after discussion with Tejun about
FBS(FIS-based switching) support preparation:
a. Kill @force_restart and always kick the engine. The only case where
@force_restart is zero is when it's called from ahci_p5wdh_hardreset()
Actually at that point, BSY is pretty much guaranteed to be set.
b. If PMP is attached, ignore busy and always do CLO. (AHCI-1.3 9.2)
Signed-off-by: Shane Huang <shane.huang@amd.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
It turns out ASUS M2A-VM isn't the only one with the 32bit DMA
problem. Make ahci_asus_m2a_vm_32bit_only() more generic using the
new dmi_get_date() and rename it to ahci_sb600_32bit_only(). Cut off
date is now pointed to by dmi_system_id->driver_data in "yyyymmdd"
format and it's now also allowed to be omitted.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Sandor Bodo-Merle <sbodomerle@gmail.com>
Cc: Shane Huang <shane.huang@amd.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
There are cases where full date information is required instead of
just the year. Add month and day parsing to dmi_get_year() and rename
it to dmi_get_date().
As the original function only required '/' followed by any number of
parseable characters at the end of the string, keep that behavior to
avoid upsetting existing users.
The new function takes dates of format [mm[/dd]]/yy[yy]. Year, month
and date are checked to be in the ranges of [1-9999], [1-12] and
[1-31] respectively and any invalid or out-of-range component is
returned as zero.
The dummy implementation is updated accordingly but the return value
is updated to indicate field not found which is consistent with how
other dummy functions behave.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
AHCI exports various capability bits that may be of interest to userspace
such as whether the BIOS claims a port is hotpluggable or eSATA. Providing
these via sysfs along with the version of the AHCI spec implemented by
the host allows userspace to make policy decisions for things like ALPM.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Hopefully results in fewer on-the-wire FIS's and no breakage. We'll see!
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Some gigabytes have on-board SIMG5723s connected to JMB ahcis. These
are used to implement hardware raid. Unfortunately some firmware
revisions on these 5723s don't bring the link down when all the
downstream ports are unoccupied while not responding to reset protocol
which makes libata think that there's device attached to the port but
is not responding and retry. This results in painfully wrong boot
detection time for these ports when they're empty.
This patch quirks those boards such that ahci gives up after the
initial timeout. Combined with parallel probing, this gives quick
enough probing and also is safe because SIMG5723 will respond to the
first try if any of the downstream ports is occupied.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Marc Bowes <marcbowes@gmail.com>
Reported-by: Nicolas Mailhot <Nicolas.Mailhot@LaPoste.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Too strong words led to spurious bug reports: Novell bugzilla #527748,
RedHat bugzilla #468800. This patch is used to soften up the dmesg on
SB600 PMP softreset failure recovery, so as to remove the scariness and
concern from community.
Reported-by: pgnet Dev <pgnet.dev@gmail.com>
Signed-off-by: Shane Huang <shane.huang@amd.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Add device IDS for Ibex Peak SATA AHCI Controllers
Signed-off-by: Jaroslav Kysela <jkysela@redhat.com>
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Add device ID for Intel 82801JI SATA AHCI controller.
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Community reported one SB600 SATA issue(BZ #9412), which led to 64 bit
DMA disablement for all SB600 revisions by driver maintainers with
commits c7a42156d9 and
4cde32fc4b.
But the root cause is ASUS M2A-VM system BIOS bug in old revisions
like 0901, while forcing into 32bit DMA happens to work as workaround.
Now it's time to withdraw 4cde32fc4b
so as to restore the SB600 SATA 64bit DMA capability.
This patch is also adding the workaround for M2A-VM old BIOS revisions,
but users are suggested to upgrade their system BIOS to the latest one
if they meet this issue.
Signed-off-by: Shane Huang <shane.huang@amd.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Tejun Heo