> -----Original Message----- > From: Guenter Roeck [mailto:linux@xxxxxxxxxxxx] > Sent: Sunday, January 17, 2016 19:13 > To: Winkler, Tomas > Cc: Greg Kroah-Hartman; Wim Van Sebroeck; Usyskin, Alexander; linux- > watchdog@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [char-misc-next, v4, 5/7] watchdog: mei_wdt: register wd device only > if required > > Hi Tomas, > > On Fri, Jan 08, 2016 at 12:49:25AM +0200, Winkler, Tomas wrote: > > From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> > > > > For Intel Broadwell and newer platforms, the ME device can inform > > the host whether the watchdog functionality is activated or not. > > If the watchdog functionality is not activated then the watchdog interface > > can be not registered and eliminate unnecessary pings and hence lower the > > power consumption by avoiding waking up the device. > > The feature can be deactivated also without reboot > > in that case the watchdog device should be unregistered at runtime. > > > > Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> > > Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx> > > --- > > V2: rework unregistration > > V3: rebase; implement unregistraion also at runtime > > V4: Rebase the code over patchset : "watchdog: Replace driver based > refcounting" > > > > drivers/watchdog/mei_wdt.c | 196 > ++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 187 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/watchdog/mei_wdt.c b/drivers/watchdog/mei_wdt.c > > index e7e3f144f2b0..85b27fc5d4ec 100644 > > --- a/drivers/watchdog/mei_wdt.c > > +++ b/drivers/watchdog/mei_wdt.c > > > [ ... ] > > > +static void mei_wdt_unregister_work(struct work_struct *work) > > +{ > > + struct mei_wdt *wdt = container_of(work, struct mei_wdt, unregister); > > + > > + mei_wdt_unregister(wdt); > > +} > > Registration is synchronous, unregistration is asynchronous. > > Assuming that is on purpose, I think it warrants an explanation. > The unregistration is detected on response from the ping, which is run under same mutex as unregistration. Tomas -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
