From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 36D55E011B6 for ; Fri, 12 Aug 2011 06:13:36 -0700 (PDT) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca [147.11.189.40]) by mail.windriver.com (8.14.3/8.14.3) with ESMTP id p7CDDge0024409 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Fri, 12 Aug 2011 06:13:42 -0700 (PDT) Received: from [128.224.147.214] (128.224.147.214) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server id 14.1.255.0; Fri, 12 Aug 2011 06:13:42 -0700 Message-ID: <4E452704.8050701@windriver.com> Date: Fri, 12 Aug 2011 09:13:40 -0400 From: Bruce Ashfield User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110617 Thunderbird/3.1.11 ThunderBrowse/3.8 MIME-Version: 1.0 To: Richard Purdie References: <606861a92864cb728203fdf5db286d684d2537eb.1313090099.git.bruce.ashfield@windriver.com> <1313106445.14274.478.camel@rex> <4E44792F.5000402@windriver.com> <1313154469.14274.489.camel@rex> In-Reply-To: <1313154469.14274.489.camel@rex> Cc: poky@yoctoproject.org, Liming Wang , saul.wold@intel.com Subject: Re: [PATCH 1/1] meta-yocto: remove apm from beagleboard MACHINE_FEATURES X-BeenThere: poky@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Poky build system developer discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Aug 2011 13:13:36 -0000 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit On 11-08-12 09:07 AM, Richard Purdie wrote: > On Thu, 2011-08-11 at 20:51 -0400, Bruce Ashfield wrote: >> On 11-08-11 7:47 PM, Richard Purdie wrote: >>> On Thu, 2011-08-11 at 15:16 -0400, Bruce Ashfield wrote: >>>> Fixes [YOCTO: #916] >>>> >>>> apm is not something that we require in our yocto reference beagleboard >>>> BSP. It currently is listed in the MACHINE_FEATURES for the board, which >>>> leads to the runtime message: >>>> >>>> Starting advanced power management daemon: No APM support in kernel >>>> >>>> Since "/proc/apm" is not present. The board config we are targeting does >>>> not have the hardware to back this, so adding the emulation support >>>> wouldn't yield useful data. We'll leave this extended functionality for >>>> other more appropriate beagleboard configs. >>> >>> On arm it used to be the case that this was the only way to expose user >>> interface to suspend/resume the machine. Its not so much about their >>> being hardware present for it as the whole kernel side was emulation of >>> the user space notification part. >>> >>> Has something changed in recent kernels in this area? >> >> I won't claim to be an expert here .. but I haven't used apmd >> on many machines in quite a while. Assuming suspend_ops is >> implemented, it is typically just something ike this: >> >> echo mem> /sys/power/state >> >> or >> >> echo standby> /sys/power/state >> >> With a wakeup via the rtc, or whatever the board offers. I'm >> cc'ing Liming on this, since he's been poking at the board recently >> and may have more hands on information to share. >> >> If we ARE removing this capability, then we'll take the other option >> that we had for this case and enable the emulation. > > I have a suspicion that certain parts of the sato code do > assume /dev/apm_bios device emulation is present to get userspace > notification of suspend/resume events which the above doesn't provide > last I checked. > > Likely this isn't an issue and I think that code in sato (matchbox panel > app iirc) is toggled by the MACHINE_FEATURES but its certainly worth > keeping in mind... Ack'd. We'll have a look at this. Drop my current pull request, and this can stand a deeper look. Bruce > > Cheers, > > Richard > > >