On Fri, Mar 17, 2017 at 09:50:07AM -0600, Mathieu Poirier wrote:

[...]

If we don't check for "nohlt" some platform may freeze, others may work.  If we
mandate that "nohlt" be present on the kernel cmd line it works in all cases.
As such mandating that "nohlt" be present is a better way to go.

Sure, so I will add below checking code in the probe function, please
let me know if you have alter better way to implement this:

+       if (IS_ENABLED(CONFIG_CPU_IDLE) &&
+                       !strstr(boot_command_line, "nohlt")) {
+               dev_err(dev, "May not be accessible in CPU power domain.\n");
+               return -EPERM;
+       }

Thanks,
Leo Yan