Messages in this thread | | | Date | Sat, 21 Mar 2015 11:43:56 +0100 | From | Hans de Goede <> | Subject | Re: [PATCH v3 0/5] clocksource: sun5i: Support parent clock rate changes |
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Hi,
On 20-03-15 21:56, Maxime Ripard wrote: > Hi, > > On Fri, Mar 20, 2015 at 03:04:28PM +0100, Daniel Lezcano wrote: >> On 03/19/2015 11:53 PM, Maxime Ripard wrote: >>> Hi Daniel, >>> >>> On Thu, Mar 05, 2015 at 11:20:51AM +0100, Maxime Ripard wrote: >>>> Hi, >>>> >>>> The Allwinner HS timers have the AHB clock as their parent >>>> clock. Since this clock is shared with other devices, we could very >>>> well have another driver requesting a rate change of that clock, >>>> making our timer change frequency at the same time. >>>> >>>> This is especially true on the A31, where the DMA controller needs to >>>> do such a rate change, making the HS timer unreliable at the time on >>>> the A31. >>>> >>>> This serie makes some cleanups and implements clock notifiers to be >>>> able to reflect such rate changes and make sure that the timer is >>>> always working. >>>> >>>> Maxime >>>> >>>> Changes from v2: >>>> - Rebased on top of v4.0-rc1 >>>> - Removed the local_irq_save/restore around clockevents_update_freq >>>> >>>> Changes from v1: >>>> - Changed the interrupt name to its previous value >>>> >>>> Maxime Ripard (5): >>>> clocksource: sun5i: Switch to request_irq >>>> clocksource: sun5i: Use of_io_request_and_map >>>> clocksource: sun5i: Remove sched_clock >>>> clocksource: sun5i: Refactor the current code >>>> clocksource: sun5i: Add clock notifiers >>> >>> Have these patches been merged? >>> >>> If not, it woulde be great if the third one ("clocksource: sun5i: >>> Remove sched_clock") was merged for 4.0. >>> >>> The sched_clock we use on some system is this timer's, and since we >>> started using cpufreq, the cpu clock (that is one of the timer's clock >>> indirect parent) now changes, along with the actual sched_clock rate. >>> >>> We can safely remove the sched_clock on those systems, since we have >>> other reliable sched_clock in the system. >> >> Ok, I applied the patch for v4.0-rc5 but I had to fix a conflict and change >> the changelog. > > It looks fine. > > Note that the rest of the serie should also be merged, this is just a > temporary measure for 4.0. > >> Mind to test it works ? >> >> git.linaro.org/people/daniel.lezcano/linux.git clockevents/v4.0-rc4 > > Unfortunately, I won't have access to my boards for ~10 days due to > travel to ELC. Chen-Yu, Hans, could you test this and see if it works?
I've just given this a test run on an A20 board, using the dmesg timestamps are off reproducer discussed before, and the problem no longer reproduces on the clockevents/4.0-rc4 branch, and everything else still seems to work fine.
Regards,
Hans
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