linux-kernel - Re: [RFC PATCH 0/6] Suspend USB Host controller on bus suspend

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

Message-ID: <51C2F807.1000301@ti.com>
Date:	Thu, 20 Jun 2013 15:39:35 +0300
From:	Roger Quadros <rogerq@...com>
To:	Alan Stern <stern@...land.harvard.edu>
CC:	<tony@...mide.com>, <balbi@...com>, <ruslan.bilovol@...com>,
	<linux-usb@...r.kernel.org>, <linux-omap@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [RFC PATCH 0/6] Suspend USB Host controller on bus suspend

On 06/19/2013 06:23 PM, Alan Stern wrote:
> On Wed, 19 Jun 2013, Roger Quadros wrote:
> 
>> Hi,
>>
>> This series attempts to suspend the OMAP EHCI host controller on USB
>> Bus suspend.
> 
> Why do you want to suspend the host controller during bus suspend?  
> They are two different operations and should be carried out at two 
> different times.  The controller should be suspended during controller 
> suspend, not during bus suspend.
> 

Good point. I didn't think it that way. I think it should work.

>> As the omap-ehci controller driver needs to do some additional work to put
>> itself into suspend/resume and make sure it is resumed to process an interrupt,
>> we need to be able to override irq, bus_suspend, and bus_resume handlers. This
>> provision is done in patch 3.
> 
> Do you still need to override these things if you do the controller
> suspend at the right time?
> 

At least not for bus_suspend and bus_resume. We will still need to override the irq
handler though. But, if we can take care of this generically in the ehci_irq handler (i.e. make
sure controller is not suspended while accessing it) then we don't need such override
for irq.

cheers,
-roger
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/