[PATCH 0/12] Add clk_prepare/clk_unprepare for mxs clock api

Shawn Guo shawn.guo at freescale.com
Tue Dec 20 09:05:03 EST 2011

On Tue, Dec 20, 2011 at 02:43:02PM +0100, Marek Vasut wrote:
> > The mutex locking problem on mxs platform has been reported on mailing
> > list for a few time.  The cause is that a mutex is being held in mxs
> > clock api clk_enable/clk_disable which are being called by some mxs
> > clock client drivers like amba-pl011 and mxs-saif in atomic context.
> > 
> > This series takes Russell's suggestion to:
> > 
> >  * Convert all mxs clock client drivers to clk_prepare/clk_unprepare.
> >    (I hope the series has covered all the drivers, but appreciate any
> >    reminding on any missing ones.)
> serial/amba-pl011.c isn't converted, that's where I originally observed the 
> issue.

The amba-pl011 on mainline had already been converted by Russell.  The
reason we are still seeing the problem is that clk_prepare/clk_unprepare
is dummy while clk_enable/clk_disable holds mutex on mxs clock api.
And this series is trying to swap the their position to have the problem

You can try this series out to see if your problem goes away :)


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