linux-kernel - RE: Ghost Lid switch on Baytrail tablet

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Date:	Tue, 21 Jul 2015 01:30:21 +0000
From:	"Zheng, Lv" <lv.zheng@...el.com>
To:	Bastien Nocera <hadess@...ess.net>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <lenb@...nel.org>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:	"dev@...utier.fr" <dev@...utier.fr>
Subject: RE: Ghost Lid switch on Baytrail tablet

Hi,

If the issue is already identified and confirmed:
For example, you've confirmed the QR_EC(0x14) can only arrive when the keyboard accessory is plugged in.
Then please ignore my previous reply.
I don't have idea about handling a LID that always returns "closed" when the keyboard accessory is not plugged in.

Thanks
-Lv

> From: Zheng, Lv
> Sent: Tuesday, July 21, 2015 8:23 AM
> 
> Hi,
> 
> The _LID returns LIDS:
>         Device (LID)
>         {
>             Name (_HID, EisaId ("PNP0C0D") /* Lid Device */)  // _HID: Hardware ID
>             Name (LIDS, Zero)
>             Method (_LID, 0, NotSerialized)  // _LID: Lid Status
>             {
>                 Return (LIDS) /* \_SB_.LID_.LIDS */
>             }
>         }
> All LIDS related code can be found:
> 	Line 132:         LIDS,   8,
> 	Line 5400:                         PARM |= (LIDS << 0x10)
> 	Line 5566:                         PARM = (LIDS << 0x08)
> 	Line 11792:             ^^LID.LIDS = Zero
> *	Line 11802:             ^^LID.LIDS = One
> 	Line 11906:             Name (LIDS, Zero)
> 	Line 11909:                 Return (LIDS) /* \_SB_.LID_.LIDS */
> The value is only set by Q14 (marked by * above):
>         Method (Q14, 0, NotSerialized)
>         {
>             P8XH (One, 0xBB)
>             P8XH (Zero, 0x14)
>             ^^LID.LIDS = One
>             Notify (LID, 0x80) // Status Change
>             P8XH (One, 0xBB)
>             P8XH (Zero, 0xA4)
>         }
> If QR_EC(0x14) cannot arrive to the OSPMs as early as possible, then the default LIDS=0 value may cause problem.
> We need EC debug log to track if QR_EC(0x14) can arrive earlier.
> 
> You can uncomment the following line from drivers/acpi/ec.c and rebuild the kernel:
> /* #define DEBUG */
> 
> Send the dmesg output (before suspending) to us.
> 
> Thanks and best regards
> -Lv
> 
> > -----Original Message-----
> > From: Bastien Nocera [mailto:hadess@...ess.net]
> > Sent: Sunday, July 19, 2015 8:43 AM
> > To: Rafael J. Wysocki; Len Brown; linux-acpi@...r.kernel.org; linux-kernel@...r.kernel.org
> > Cc: dev@...utier.fr
> > Subject: Ghost Lid switch on Baytrail tablet
> >
> > Hey,
> >
> > This tablet:
> > http://www.amazon.com/WinBook-10-1-Inch-Windows-full-size-Display/dp/B00N9ZG5U2/
> > doesn't have a physical lid switch unless you plug the keyboard accessory to it.
> >
> > But it thinks that there is a lid, and that it's closed, making logind
> > suspend the machine after about 30 seconds.
> >
> > I'm currently testing this on a 4.0 kernel, as there have been
> > regressions on Baytrail with 4.1 and 4.2rcs.
> >
> > The DSDT for that tablet:
> > https://people.gnome.org/~hadess/Winbook%20TW100%20DSDT.dsl
> >
> > Any ideas how to handle this sort of device?
> >
> > Cheers