From mboxrd@z Thu Jan 1 00:00:00 1970 From: mturquette@linaro.org (Mike Turquette) Date: Wed, 03 Sep 2014 10:03:39 -0700 Subject: [PATCH V2 0/4] clk: mvebu: Improve clock drift In-Reply-To: <902cee907da9c532822dcf5db722b47c@doppler.thel33t.co.uk> References: <1409645719-20003-1-git-send-email-gregory.clement@free-electrons.com> <902cee907da9c532822dcf5db722b47c@doppler.thel33t.co.uk> Message-ID: <20140903170339.11368.17168@quantum> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Quoting Leigh Brown (2014-09-03 07:40:56) > On 2014-09-02 09:15, Gregory CLEMENT wrote: > > Few users reported a timer drift on the Armada 370 based board such as > > the mirabox or the Netgear ReadyNAS 102. This is the second series > > with few improvements after the review of the 1st version. > > > > The reason is that when the SSCG (Spread Spectrum Clock Generator) is > > enabled, it shifts the frequency of the clock. The percentage is no > > more than 1% but when the clock is used for a timer it leads to a > > clock drift. > > > > This series allows to correct the affected clock when the SSCG is > > enabled. This drift can happen on all the mvebu SoC on the cpu clock > > block (ie cpu, ddr and l2 cache). Currently the only notable effect is > > for the Armada 370 because this SoC use the l2cache clock as source > > for the timer. That's why even if the series allow any of the mvebu > > SoC to benefit to this correction, Armada 370 is the only user of it. > > > > The first 2 patches should go through the clk subsystem, whereas the > > third one should go to the arm-soc through the mvebu tree. > > > > The last one is just to fix a typo I found while I was reading the clk > > code. > > This is working superbly for me on my Mirabox, and ntpd is now > completely stable. > > Tested-by: Leigh Brown > Clock patches look good to me. Regards, Mike