When EC is in Polling mode, OS will check the EC status continually by using
the following source code:
       clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
       while (time_before(jiffies, delay)) {
               if (acpi_ec_check_status(ec, event))
       	            return 0;
               msleep(1);
       }
But msleep is realized by the function of schedule_timeout. At the same time
although one process is already waken up by some events, it won't be scheduled
immediately. So maybe there exists the following phenomena:
     a. The current jiffies is already after the predefined jiffies.
	But before timeout happens, OS has no chance to check the EC
	status again.
     b. If preemptible schedule is enabled, maybe preempt schedule will happen
	before checking loop. When the process is resumed again, maybe
	timeout already happens, which means that OS has no chance to check
	the EC status.

In such case maybe EC status is already what OS expects when timeout happens.
But OS has no chance to check the EC status and regards it as AE_TIME.

So it will be more appropriate that OS will try to check the EC status again
when timeout happens. If the EC status is what we expect, it won't be regarded
as timeout. Only when the EC status is not what we expect, it will be regarded
as timeout, which means that EC controller can't give a response in time.

http://bugzilla.kernel.org/show_bug.cgi?id=9823
http://bugzilla.kernel.org/show_bug.cgi?id=11141Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NZhang Rui  <rui.zhang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

On some ASUS laptops the ECDT gives the incorrect command/status & Data I/O
register address.

AK: it seems like the command/data addresses are exchanged.

In such case it will cause that EC device can't be
initialized correctly.
To add the EC dmi table is to fix this issue. If the laptop falls into the
EC dmi table, the EC command/data I/O address will be fixed.

AK: Add comments describing this better

http://bugzilla.kernel.org/show_bug.cgi?id=9399Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
tested-by    : Jan Kasprzak  <kas@fi.muni.cz>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

http://bugzilla.kernel.org/show_bug.cgi?id=10724Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Problem seems to be that hw fails to clear GPE after we service it and write 1
into corresponding bit. Thus, as soon as we get interrupts enabled again, we
receive a new one. Google gives too many results for "acer interrupt storm" for
this being one-broken-machine case.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9998Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

If we can not use interrupt mode of EC for some reason, start polling
EC for events periodically.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

This fixes keyboard event handling on some systems.

Note that this delay was thought unnecessary, and removed
from linux-2.6.20 with 50c1e113
'ACPI: ec: Drop udelay() from poll mode. Loop by reading status field instead.'
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit 2c81ce4c.

It caused several new troubles (eg suspend slowdown bisected down to
this patch by Pavel Machek), so just revert it for now.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On some Acer systems, the HW fails to clear the GPE source,
causing an interrupt storm.

So in EC interrupt mode, we count how many interrupts we
receive when waiting.  If we get more than 5, we give
up on interrupt mode and revert to polling mode.

Also, for polling mode to work on Acers, we need
to insert a delay.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit 208c70a4.

http://bugzilla.kernel.org/show_bug.cgi?id=10100Signed-off-by: NLen Brown <len.brown@intel.com>

Fall back to ACPI_ROOT_HANDLE only in case of error.

ACPI: EC: EC description table is found, configuring boot EC
ACPI Error (evregion-0316): No handler for Region [ECOR] (ffff81007a651620) [EmbeddedControl] [20070126]
ACPI Error (exfldio-0289): Region EmbeddedControl(3) has no handler [20070126]

http://bugzilla.kernel.org/show_bug.cgi?id=9916Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

The "DEBUG" symbol needs to be defined before #including <linux/kernel.h> to
get the pr_debug() working.
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NLen Brown <len.brown@intel.com>

Add leading zeros to pr_debug() calls. For example if x=0x0a, the format
"0x%2x" will result the string "0x a", the format "0x%2.2x" will result "0x0a".
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NLen Brown <len.brown@intel.com>

Return OBF_1 optimization workaround

http://bugzilla.kernel.org/show_bug.cgi?id=8459Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Burst mode temporary (50 ms) locks EC to do only transactions with
driver, without it some hardware returns abstract garbage.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9341Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Specification allows only byte access for EC region, so
make it separate from bug-compatible multi-byte access.
Also do not allow return of garbage in supplied *value.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9341Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some _STA methods called during bus_scan() might require EC region handler,
which might be enabled later in the scan.
Enable it explicitly before scan to avoid errors.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9627Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some controllers fail to send confirmation GPE after address or data write.
Detect this and don't expect such confirmation in future.
This is a generalization of previous workaround
(66c5f4e7), which did only read address.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9327Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: NRomano Giannetti <romano.giannetti@gmail.com>
Tested-by: Mats Johannesson
Signed-off-by: NLen Brown <len.brown@intel.com>

Sometimes it is usefull to see raw protocol dump.
Uncomment '#define DEBUG' at the beginning of file to make EC
really verbose.
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit f2d68935.

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Option to init EC early inserted to handle #8598 ASUS problem,
introduced several others.

EC driver in this particular case has fake _INI method, not present on
other machines, which don't need or break from this workaround, so lets use
its presence as a flag for early init.

http://bugzilla.kernel.org/show_bug.cgi?id=9262
http://bugzilla.kernel.org/show_bug.cgi?id=8598
https://bugzilla.novell.com/show_bug.cgi?id=334806Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some controllers fail to send confirmation GPE after address write.
Detect this and don't expect such confirmation in future.
This is a generalization of previous workaround
(66c5f4e7), which did only read address.

http://bugzilla.kernel.org/show_bug.cgi?id=9327Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: NRomano Giannetti <romano.giannetti@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

This patch fixes a use-after-free introduced by
commit 30c08574
(ACPI: EC: Add new query handler to list head)

Spotted by the Coverity checker.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Insert printk() for every change in operational mode.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some controllers do not send interrupts for OBF=1 event, but send
them for IBF=0. Add workaround for them.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=8459Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

With the auto selection of operation mode, absence of GPEs does not
really degrade performance, so let PM code to handle
enabling/disabling GPEs.
This is a revert of 5d57a6a5,
which was meant to be temporary.

Reference: http://bugzilla.kernel.org/show_bug.cgi?id=7977Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>

Start in POLL mode, and if we receive confirmation GPE,
switch to INT mode.
If confirmations are not sent, switch back to POLL.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

There is no interrupt after last read according to spec, so
don't set bit that we are expecting one.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Number of flags is about to be increased, so it is better to
put them all into bits.
No functional changes.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

ASUS notebooks have numerous problems with EC initialization
This patch tries to work around three known issues reported
in bugzilla 8598, 8709 and 8909/8919.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

acpi_get_devices() returns success if it did not find any device.
We have to check for this case.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: NDaniel Ritz <daniel.ritz-ml@swissonline.ch>
Tested-by: NLuca <kronos.it@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a manual revert of 7c010de7,
a fix that broke another ASUS in 8909 and 8919.
Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>

Restore deleted call to register query methods.

http://bugzilla.kernel.org/show_bug.cgi?id=8886Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>