Return-Path: Message-ID: <4EA6CC5B.2020400@canonical.com> Date: Tue, 25 Oct 2011 22:48:59 +0800 From: Jesse Sung MIME-Version: 1.0 To: Oliver Neukum CC: linux-bluetooth@vger.kernel.org, 812132@bugs.launchpad.net Subject: Re: [PATCH] Bluetooth: set reset_resume handler References: <4EA67552.1090703@canonical.com> <201110251040.14016.oneukum@suse.de> <4EA69B6D.3000905@canonical.com> <201110251343.49236.oneukum@suse.de> In-Reply-To: <201110251343.49236.oneukum@suse.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Sender: linux-bluetooth-owner@vger.kernel.org List-ID: On 10/25/2011 07:43 PM, Oliver Neukum wrote: > Am Dienstag, 25. Oktober 2011, 13:20:13 schrieb Jesse Sung: >> On 10/25/2011 04:40 PM, Oliver Neukum wrote: >>> Am Dienstag, 25. Oktober 2011, 10:37:38 schrieb Jesse Sung: >>>> >>>> On some machines, it seems that usb hubs do not get power while >>>> being suspended. We can get something like this in dmesg: >>>> usb usb2: root hub lost power or was reset >>>> >>>> When this is the case, .reset_resume is called instead of .resume. >>>> If .reset_resume is not set, bluetooth modules would stay in an unusable >>>> state because the resume function is not called. >>> >>> Have you experimentally verified that? This state of affairs is years >>> old and should result in a virtual unplug/replug cycle. What are you >>> seeing? >> >> Hi Oliver, >> >> Humm... You're right, there is an unplug-replug cycle, but bluetooth >> doesn't work until I restart bluetoothd. If the resume function is >> called through .reset_resume, then bluetooth works right after resume. > > Hi > > Yes, but we fail to indicate to user space that connections may have been > dropped. I doubt we can simply pretend the loss of power hasn't occured. > Have you tested what happens if you go to S3 while eg. a file is transfered > or audio played with your patch? Hi Oliver, Indeed, loss of power event should not be ignored. Just tested file transferring. If there's no active connection, everything goes fine. But if a file is transferring while going to S3, bluetooth is not working after resume. Use applet to disable and re-enable bluetooth makes it work again... Wondering what is the right way to handle loss of power... Regards, Jesse