RE: [linux-pm] [PATCH] i2c: OMAP: fix static suspend vs. runtime suspend
From: Rajendra Nayak <hidden>
Date: 2011-01-31 15:28:29
Also in:
linux-arm-kernel, linux-omap
From: Rajendra Nayak <hidden>
Date: 2011-01-31 15:28:29
Also in:
linux-arm-kernel, linux-omap
-----Original Message----- From: Alan Stern [mailto:stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org] Sent: Monday, January 31, 2011 8:43 PM To: Rajendra Nayak Cc: Kevin Hilman; Ben Dooks; linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org;
linux-pm-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org; linux-
omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Subject: Re: [linux-pm] [PATCH] i2c: OMAP: fix static suspend vs.
runtime suspend
On Mon, 31 Jan 2011, Rajendra Nayak wrote:quoted
Can you elaborate a bit more on how/why runtime PM transitions are disabled during system suspend, and how is it taken care of that a runtime resume of a device works however a subsequent runtime (re)suspend does not?I'll answer for Kevin. This is done by the PM core, in order to prevent runtime power transitions from interfering with a system power transition. The PM core increments the device's usage_count; this prevents the device from being runtime-suspended but it allows runtime-resume calls to go through.
Thanks, I did remember seeing the pm_runtime_get_noresume() in dpm_prepare(). Just did not correlate it was the same Kevin was trying to say. Regards, Rajendra
Alan Stern