linux-kernel - Re: [PATCH 4.1 099/267] phy: twl4030-usb: remove incorrect pm_runtime_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Tue, 11 Aug 2015 19:29:10 -0500
From:	Felipe Balbi <balbi@...com>
To:	NeilBrown <neil@...wn.name>
CC:	Alexander Holler <holler@...oftware.de>,
	Felipe Balbi <balbi@...com>,
	Kishon Vijay Abraham I <kishon@...com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<linux-kernel@...r.kernel.org>, <stable@...r.kernel.org>
Subject: Re: [PATCH 4.1 099/267] phy: twl4030-usb: remove incorrect
 pm_runtime_get_sync() in probe function.

Hi,

On Wed, Aug 12, 2015 at 08:09:27AM +1000, NeilBrown wrote:
> On Tue, 11 Aug 2015 23:34:17 +0200 Alexander Holler
> <holler@...oftware.de> wrote:
> 
> > Am 11.08.2015 um 10:29 schrieb NeilBrown:
> > 
> > > With the current mainline code (plus my twl4030 charger enhancements,
> > > which are not deeply relevant), the refcount does go to zero when
> > > nothing is plugged in, and goes to 2 when a regular USB cable is
> > > plugged in.
> > 
> > Also I think it's just a little miswording (or extended typo), I'm not 
> > using a regular USB cable, but an OTG cable when using the host mode of 
> > the musb on the Beagleboard. Just to avoid confusion. Or do you talk 
> > about the client mode when it goes to 2?
> 
> With an OTG cable, the usage_count would probably got to '1' because
> the charger wouldn't be interested.
> 
> However the important point is that the usage_count goes to zero when
> no cable is plugged in.
> 
> > 
> > Besides that, I'm sorry to not be of further help. My deeper knowledge 
> > about the musb sources in the kernel and u-boot (and the HW in 
> > question), has gone lost and I've currently no real reason to refresh 
> > that. ;)
> 
> Just reporting the problem is sometimes 90% for the bug fixed.
> I'm confident I know what is happening.  What isn't clear is how best
> to fix it without breaking something else... I suspect Felipe can help
> with that.

It'll take me a while to be able to look at this. I don't have any
platform with TWL4030 (IIRC, AM335x uses tps65218 instead). Besides, I
have a slightly bigger problem to look at (MUSB + some hubs + CP2108
fails sometimes).

If I get some time, I'll try to have a look, but it might take a few
weeks.

cheers

-- 
balbi

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)