On Wednesday, January 15, 2014 12:35:16 AM Liu, Chuansheng wrote: > Hello Rafael, > > > -----Original Message----- > > From: Rafael J. Wysocki [mailto:r...@rjwysocki.net] > > Sent: Wednesday, January 15, 2014 6:55 AM > > To: Liu, Chuansheng > > Cc: gre...@linuxfoundation.org; Brown, Len; pa...@ucw.cz; > > linux...@vger.kernel.org; linux-kernel@vger.kernel.org; Li, Zhuangzhi > > Subject: Re: [PATCH] PM: Enable asynchronous noirq resume threads to save > > the resuming time > > > > On Tuesday, January 14, 2014 03:18:08 PM Chuansheng Liu wrote: > > > > > > Currently, the dpm_resume_noirq() is done synchronously, and for PCI > > > devices > > > pci_pm_resume_noirq(): > > > > > > pci_pm_resume_noirq() > > > pci_pm_default_resume_early() > > > pci_power_up() > > > pci_raw_set_power_state() > > > Which set the device from D3hot to D0 mostly, for every device, there will > > > be one 10ms(pci_pm_d3_delay) to wait. > > > > > > Hence normally dpm_resume_noirq() will cost > 100ms, which is bigger for > > mobile > > > platform. > > > > pci_pm_d3_delay usually is not 10 ms. What is 10 ms is dev->d3_delay, but > > that also is not on every platform now. > Yes, it is d3_delay exactly, thanks your correction. > > > > > That said the approach here makes sense, but I have two questions: > > > > 1. On what systems has it been tested? > I have been tested on Baytrail platform, and at the beginning the d3_delay is > set to 0, > but we really meet the HANG issue if we operate the device immediately > sometimes, > so currently most PCI devices in Baytrail has the 10ms delay. > And it caused the whole resume time bigger than Clovertrail platform;
Does setting d3_delay to something smaller that 10 ms work on BayTrail? You can try to set 5 ms and then 2.5 ms if that works and so on. That still would be an improvement from the 10 ms. > > 2. What about suspend_late/resume_early? If the _noirq things are to be > > executed asynchronously, those should be too. > I noticed it just taken little time often, and I cannot find out some reasons > for changing them > in theory, so if you like it, I will update them into patch V2 also:) Yes, please do that. Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
