Re: SYSFS "errors"

On Mon, 18 Feb 2013, Felipe Balbi wrote:

Hi, On Mon, Feb 18, 2013 at 09:49:16AM -0800, Greg KH wrote:

quoted

quoted

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

In theory this could be done, although the times would be when runtime 
autosuspend is turned on or off, not when pm_runtime_enable is called.

Alan Stern