From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [rft]power management for usbtouch Date: Mon, 30 Jun 2008 11:29:54 -0400 Message-ID: <20080630112709.ZZRA012@mailhub.coreip.homeip.net> References: <200806290047.56736.oliver@neukum.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200806290047.56736.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Oliver Neukum Cc: Alan Stern , Ville Syrj?l? , daniel.ritz-OI3hZJvNYWs@public.gmane.org, Jiri Kosina , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-input@vger.kernel.org On Sun, Jun 29, 2008 at 12:47:55AM +0200, Oliver Neukum wrote: > Am Samstag 28 Juni 2008 18:33:30 schrieb Alan Stern: > > On Sat, 28 Jun 2008, Oliver Neukum wrote: > > > > > In hindsight adding that interface at all was an error. I was in favor > > > of it and that was a mistake. Maybe it should be removed. > > > Complicating good drivers for its sake I therefore consider an error. > > > Possibly we should consider a forcible suspension a form of disconnection. > > > > Are you suggesting that the "off" value in /sys/.../power/level > > shouldn't be allowed? I don't see it that way -- there's no other > > mechanism for userspace to force a USB device into the low-power state. > > Unfortunately. > > > Forcing a disconnection during suspend might be a good idea. But if > > you do, is there any reason to consider manual suspension different > > from system sleep? > > During system sleep user space is asleep and cannot make demands > on drivers. If you force a device to sleep, the driver cannot work. Therefore > it should not be bound to such a device. It's cleaner to disconnect. I'd agree with this. Otherwise we need somehow to be able to resync the state of the device (like have LEDs and repeat rate reset, re-upload force-feedback effects, etc, etc) once device is resumed. So... what is the consensus? Do we need to worry about manual device-level suspension or it will be reworked/removed? -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html