Message-ID: <4C722FD6.8090808@canonical.com>
Date:	Mon, 23 Aug 2010 16:22:46 +0800
From:	Ike Panhc <ike.pan@...onical.com>
To:	Mario 'BitKoenig' Holbe <Mario.Holbe@...Ilmenau.DE>,
	David Woodhouse <dwmw2@...radead.org>,
	"platform-driver-x86@...r.kernel.org" 
	<platform-driver-x86@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	Thomas Renninger <trenn@...e.de>,
	Alan Cox <alan@...ux.intel.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Corentin Chary <corentincj@...aif.net>,
	Randy Dunlap <randy.dunlap@...cle.com>,
	"Brown, Len" <len.brown@...el.com>,
	Matthew Garrett <mjg@...hat.com>
Subject: Re: [PATCH 0/8] [Resend] ideapad: using EC command to control rf/camera
 power

On 08/20/2010 05:08 PM, Mario 'BitKoenig' Holbe wrote:
> On Fri, Aug 20, 2010 at 03:01:07PM +0800, Ike Panhc wrote:
>> Could you attach or upload the DSDT of S12 somewhere I can reach?
> 
> http://sandbox.fem.tu-ilmenau.de/s12/dsdt-s12-via.dsl
Thanks for the DSDT and the following information.

I am not an expert on AML but after looking to the DSDT, I think I will
focus on what XCMD do.

I notice there are some interesting method/variable (Ex: BTEN/BTST..)
about bluetooth, but not have a good story about what's going on.

I think the only problem we have now is bluetooth sometimes not coming
back when rebooting after turn off bluetooth via sw rfkill. Try to find
out if there is anything need to be done before turn it on.

> 
>> I check DSDT for S10-3 and B550, return value of _CFG is fixed.
>> [Ref: http://people.ubuntu.com/~ikepanhc/DSDTs]
> 
> Looks more fixed than on my S12, indeed.
> I don't really speak AML, but while S10-3 ILDD (called from _CFG) seems
> to read fixed values only, here on S12 PHSR (called from _CFG) seems to
> do some kind of I/O operation. I'm not sure about this, but it somehow
> looks like.
> 
>> On 08/20/2010 03:31 AM, Mario 'BitKoenig' Holbe wrote:
>>> Once the cfgbit is 0xc0000 it's stable, i.e. modprobe -r ideapad-laptop;
>>> modprobe ideapad-laptop doesn't change anything.
>> sounds like we need an exception handle for detecting camera
> 
> Why? The camera is always detected - bit 19 is always set, 0xc0000 and
> 0xd0000 only differ in bit 16. Bit 19 btw. seems to be the only fixed
> bit in S12-VIA _CFG :)
> 
>>> [  682.260288] ideapad_acpi_add(): cfg=0xc0000
>> As I know the cfgbit for lower 16bit shall not be all zero.
> 
> Mh, judging from S12-VIA _CFG they definitely are zero here.
> 
>>> So, forcing the existence of the killswitch enables the bluetooth
>>> device. I'm also able to switch if off again - the bluetooth device
>>> disappears. Trying to switch it back on then fails - the bluetooth
>>> device does not appear again. But this case doesn't work all that well
>>> anyways even with cfgbit 0xd0000:
>> bluetooth device shall disappear after disable from EC. But if can not be enabled
>> again, ahh.....
> 
>>> [  155.628052] usb 4-1: new full speed USB device using uhci_hcd and address 4
>>> [  170.740049] usb 4-1: device descriptor read/64, error -110
>>> [  185.956033] usb 4-1: device descriptor read/64, error -110
>> This looks like the device is power up, but usb host unable to recognize..
> 
> The bluetooth device seems not to initialize well enough to answer (110
> is ETIMEDOUT).
> 
>>> Sometimes it doesn't even come back at all on unblock. Seems like the
>>> bluetooth device doesn't really like to be powered off and on that way.
>> did you see any kernel message said timeout when it does not come back at all?
> 
> No, when I said "does not appear again" and "it does not come back at
> all" I meant I see not a single message in dmesg about anything
> happening.
> 
>> If the rfkill for the whole bluetooth module makes trouble, I prefer not to
>> do it. User will feel confused if the device does not come back and the
>> rfkill of hci0 offers the function user need.
> 
> Hmmm, maybe provide a module parm to block rfkill devices and default it
> to 1 on S12? Users would not need to care too much then but can change
> it if they like...
> 
>>> Please let me know if I can provide more testing - and what kind of :)
> 
> Okay, did some more...
> 
> I played with the hardware killswitch under Linux. The bluetooth device
> disappears and re-appears there and always seems to initialize
> correctly. No USB read errors this way.
> 
> I also played with the soft killswitch under Windows. The bluetooth
> device disappears from device manager and re-appears on unblock
> (together with the Windows device plug sounds). This looks to me like
> the ACPI killswitch is used for it.
> No initialization-problems here, the device always comes back fully
> operational. So, Windows doesn't seem to suffer from a bad
> initialization.
> 
> I'm not exactly sure what this means - especially because I don't know
> how the hardware killswitch works internally.
> It *could* mean, the initialization problem is proably something that
> could be dealt with in the USB layer long term (and would then probably
> not have to be worked around anymore in ideapad_laptop). I'm not sure
> about this, because this would mean the hard killswitch power-cut
> somehow differs from the soft killswitch power-cut.
> 
> 
> Mario

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