Date: Mon, 29 Jun 2015 11:06:01 +0200
Message-ID: <s5hoajyg9za.wl-tiwai@suse.de>
From: Takashi Iwai <tiwai@suse.de>
To: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Jan Kiszka <jan.kiszka@web.de>, Hui Wang <hui.wang@canonical.com>,
        Raymond Yau <superquad.vortex2@gmail.com>, alex.hung@canonical.com,
        ALSA Development Mailing List <alsa-devel@alsa-project.org>,
        Hui Wang <jason77.wang@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        david.henningsson@canonical.com
Subject: Re: [alsa-devel] [V2 PATCH] ALSA: hda - Enable mute/mic-mute LEDs for more Thinkpads with Conexant codec
In-Reply-To: <20150627155044.GA3054@khazad-dum.debian.net>
References: <53B52146.9050300@canonical.com>
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	<CAN8cciZYZ4setSj7dgPqQUVrBrr98tSvofLrD_0zvyQqkWfd2Q@mail.gmail.com>
	<5560A93E.7060607@web.de>
	<558A4216.8010401@web.de>
	<558A6E80.7010003@canonical.com>
	<558BDFD4.9060301@web.de>
	<558CB778.5020307@canonical.com>
	<20150626224946.GA11254@khazad-dum.debian.net>
	<558E3BDE.5070708@web.de>
	<20150627155044.GA3054@khazad-dum.debian.net>
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At Sat, 27 Jun 2015 12:50:44 -0300,
Henrique de Moraes Holschuh wrote:
> 
> On Sat, 27 Jun 2015, Jan Kiszka wrote:
> > > Please explain _in detail_ what you mean with "changing a power button to a
> > > reset button by acessing the SSMS ACPI method in a X121e".
> > > 
> > > Are we trigering a bug somewhere that crashes the x121e and causes it to
> > > reboot?
> > 
> > Well, there aren't much details to describe in this case: When this
> > patch is applied and I press the power button, the device performs a
> > hard reset. It doesn't reveal if the kernel crashes catastrophically,
> > causing a triple fault or so, or if the firmware decides to reset the
> > platform. Reverting the patch or preventing its effect via a quirk
> > filter like I posted [1] makes the issue go away.
> 
> Ok, so we crashing the firmware, and on a box that is not likely to get
> further updates.  Well, this is a pretty clear case: blacklist.
> 
> Since calling SSMS in the X121e is unsafe, it needs to be blacklisted in
> thinkpad-acpi.  I will need dmidecode output for that (please XXX-out UUIDs
> and serial numbers in the dmidecode output before you send it to me, but do
> keep model numbers intact).
> 
> We can also have a blacklist in ALSA to avoid the whole symbol_request() for
> something that will have to fail, of course.  I leave that for the ALSA
> maintainers to decide.

IMO, it's simpler to just leave the decision in thinkpad_acpi.

> That said, you blacklisted in ALSA by full codec->subsystem_id.  Which
> thinkpads have the 0x17aa21ec subsystem ID on the codec?  Just the x121e?

It's not guaranteed, but Lenovo doesn't share the same PCI SSID for
multiple models, AFAIK.


thanks,

Takashi
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