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

Nicolas Ferre nicolas.ferre at atmel.com
Fri Dec 19 06:08:15 PST 2014

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 at 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 at raritan.com>
>>>> Acked-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
>>>> Acked-by: Boris Brezillon <boris.brezillon at free-electrons.com>
>>>> Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
>>>> Cc: Felipe Balbi <balbi at ti.com>
>>>> Cc: <stable at 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...

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.

Thanks, bye.
Nicolas Ferre

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