From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawn.guo@linaro.org (Shawn Guo) Date: Thu, 6 Sep 2012 23:31:06 +0800 Subject: [PATCH RFC] clk: use spinlock for clk_get_rate In-Reply-To: References: <1346919146-25972-1-git-send-email-shawn.guo@linaro.org> Message-ID: <20120906153102.GA26709@S2101-09.ap.freescale.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Sep 06, 2012 at 11:28:10AM +0200, Ulf Hansson wrote: > Hi Shawn, > > Interesting problem you found. :-) > > Just a note, that in my suggested patch: "[PATCH 1/4] clk: Provide > option for clk_get_rate to issue hw for new rate", > the prepare mutex will be required to keep. > Right. Just realized that the prepare mutex is also being used to protect clock tree topology in clk_get_rate, so it's required anyway. We may need to look for a fixing in smp_twd driver. > Not sure if that should be considered as a part of the solution to the > cpufreq problem, but anyway, thought you should know. > -- Regards, Shawn