Re: [RESEND PATCH] usb: gadget: at91_udc: move prepare clk into process context

[Luis Henriques <luis.henriques@canonical.com>]

On Fri, Dec 19, 2014 at 03:08:15PM +0100, Nicolas Ferre wrote:
> Le 19/12/2014 15:02, Ronald Wahl a écrit :
> > On 19.12.2014 14:51, Luis Henriques wrote:
> >> Hi Felipe,
> >>
> >> On Thu, Nov 20, 2014 at 01:50:49PM -0600, Felipe Balbi wrote:
> >>> On Wed, Nov 19, 2014 at 04:37:27PM +0100, Nicolas Ferre wrote:
> >>>> From: Ronald Wahl <ronald.wahl@raritan.com>
> >>>>
> >>>> Commit 7628083227b6bc4a7e33d7c381d7a4e558424b6b (usb: gadget: at91_udc:
> >>>> prepare clk before calling enable) added clock preparation in interrupt
> >>>> context. This is not allowed as it might sleep. Also setting the clock
> >>>> rate is unsafe to call from there for the same reason. Move clock
> >>>> preparation and setting clock rate into process context (at91udc_probe).
> >>>>
> >>>> Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
> >>>> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> >>>> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> >>>> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> >>>> Cc: Felipe Balbi <balbi@ti.com>
> >>>> Cc: <stable@vger.kernel.org> # v3.17+
> >>>> ---
> >>>> Hi Felipe,
> >>>>
> >>>> I forgot to answer you on this patch. So I resend it now with the proper
> >>>> "stable" tag. You can also queue it during this -rc phase if you feel it is
> >>>> still possible.
> >>>
> >>> I think it's late for v3.18, so it'll go on v3.19 and get backported to
> >>> 3.17 and 3.18. Sorry :-s
> >>>
> >>
> >> Although this commit (b2ba27a5c56f "usb: gadget: at91_udc: move
> >> prepare clk into process context") is tagged for stable v3.17+, it
> >> seems like it could be applied to earlier kernels.
> >>
> >> 3.16, 3.13 and 3.12 seem to be affected by the same issue (and they
> >> all include commit 7628083227b6 "usb: gadget: at91_udc: prepare clk
> >> before calling enable").  Is there any reason for not applying it in
> >> these trees?
> > 
> > Not to forget 3.14 (LTS) which was the branch where I primarily found 
> > the issue...
>

Yes, of course!  Sorry.

> Well it's maybe an issue with the re-naming of the directory to
> drivers/usb/gadget/udc/ introduced by patch:
> 90fccb529d24 (usb: gadget: Gadget directory cleanup - group UDC drivers)
> 
> The patch doesn't apply out of the box but it surely can be applied in
> those earlier kernels.
> 
>

Right, the file was renamed but the backport seems to be trivial.
Thanks for confirming.

Cheers,
--
Luís

> Thanks, bye.
> -- 
> Nicolas Ferre