Em Mon, 18 Feb 2013 20:46:33 +0200 Felipe Balbi <balbi@xxxxxx> escreveu: > Hi, On Mon, Feb 18, 2013 at 09:49:16AM -0800, Greg KH wrote: > > > Input/output error - /sys/devices/cpu/power/autosuspend_delay_ms > > > > The issue with this file is, if the power.use_autosuspend flag is not > > set for the device, then it can't be read or written to. This flag > > changes dynamically with the system state > > (__pm_runtime_use_autosuspend() can change it), so we can't just not > > show the file if the flag is not set properly, sorry. > > > > So the "error" is correct here, as is the 0644 file value. > > hmm... we could create the file at pm_runtime_enable() time and remove > it on pm_runtime_disable() time, no ? Addin Rafael to Cc ... > > > > > No such device - /sys/devices/system/edac/mc/mc0/sdram_scrub_rate > > > > Odd, go ask the edac developers > > will do ;-) Well, the question is missing ;) /me assumes that you want to talk about suspending/resume and EDAC, right? In general, memory controllers don't supports suspend, as far as I can tell. Still, I've seen a few ones that support, but the current drivers and/or the EDAC core currently doesn't offer any support to it, as such setup is done by the BIOS, when it detects the used DIMM banks. I suspect that, when the OS puts the machine on a suspend state, the BIOS may also suspend also the memory controller or put it into a low power consumption mode, but it does it without any help from the EDAC drivers. For most of what's there at EDAC, I don't think it is worth to add any PM support inside it. There are, however, two cases were we may need to add some support: 1) if user changed the SDRAM scrub rate before suspending, it makes sense to restore it after resume, on the memory controller drivers that support such feature (not all supports it); 2) hot-pluggable DIMMs. EDAC currently doesn't support. This could be needed on some future. In this case, the core may need to re-scan the memory controller, changing the memory properties. I've no idea if is there any real case needing it, nor what event would trigger the memory-controller re-scan. Resume is likely one of the candidates for it, on machines that support hot-pluggable memories. Regards, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
