Tomasz, On Fri, Dec 20, 2013 at 1:19 PM, Tomasz Figa <tomasz.figa@xxxxxxxxx> wrote: > Hi, > > On Friday 20 of December 2013 15:56:38 sunil joshi wrote: >> Hi Abhilash, >> I saw another patch in chrome tree ..by Andrew Bresticker >> which may be relevant here .. >> >> Just wondering if you missed adding this ? or this is not needed ? >> You did not face any issue in getting core to suspend ? >> >> ------------------------------------------------------------------------------------------ >> commit 95402d816b9f1a05ce633f7ff64b4c939c142482 >> Author: Andrew Bresticker <abrestic@xxxxxxxxxxxx> >> Date: Mon Jul 15 13:14:36 2013 -0700 >> >> arm: exynos: disable all interrupts on Exynos5420 before suspend >> >> Disable all interrupts from the GIC before entering suspend on >> Exynos5420 as is done on Exynos5250. If interrupts are enabled, we >> may receive an interrupt after entering WFI but before the PMU has >> suspended the system, causing suspend to fail. >> >> BUG=chrome-os-partner:20523 >> TEST=Run suspend_stress_test on Pit and observe that entering suspend >> no longer occasionally fails with the "Failed to suspend the system" >> error in exynos_cpu_suspend(). > > A question about this for Chromium and LSI guys: > > If you find out that there is already a pending interrupt before you enter > the sleep mode, isn't it more reasonable to cancel the process ASAP and > handle the event instead of entering the sleep just to leave it? > > I believe this should be both more efficient with respect to power usage > and latency, because sleep-wakeup transition takes time and power. > > Do you have any reason to think the opposite? I'm not actually sure I know every last detail, but... >From what I remember on 5250 there was some type of mystery interrupt that was hitting in the system but that wasn't identifiable as any particular interrupt source. I think that this was an attempt to deal with that with a heavy hammer. I don't think it was a very elegant solution and it would be nice to do better. Ah, here's the original CL: <https://chromium-review.googlesource.com/#/c/34541/>. ...as you can see I wasn't super happy about it at the time but was OK with it going in since it was very late in the Chromebook release cycle and we needed suspend/resume to be reliable. Another fairly questionable CL: <https://chromium-review.googlesource.com/#/c/37991/> It would be super great if we could get suspend/resume reliable upstream without those hacks. -Doug -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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