From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nigel Cunningham Subject: Re: [linux-pm] [patch/rft 2.6.17-rc2] swsusp resume must not device_suspend() Date: Wed, 26 Apr 2006 13:44:20 +1000 Message-ID: <200604261344.24694.nigel@suspend2.net> References: <200604241429.52022.david-b@pacbell.net> <200604261116.59070.nigel@suspend2.net> <200604252032.42695.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart29389695.nQdGM9HlHt"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200604252032.42695.david-b@pacbell.net> Sender: linux-usb-devel-admin@lists.sourceforge.net Errors-To: linux-usb-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: David Brownell Cc: "Rafael J. Wysocki" , linux-pm@lists.osdl.org, Andrew Morton , linux-usb-devel@lists.sourceforge.net List-Id: linux-pm@vger.kernel.org --nextPart29389695.nQdGM9HlHt Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hi. On Wednesday 26 April 2006 13:32, David Brownell wrote: > On Tuesday 25 April 2006 6:16 pm, Nigel Cunningham wrote: > > Hi. > > > > On Wednesday 26 April 2006 09:55, David Brownell wrote: > > > On Tuesday 25 April 2006 3:18 pm, Nigel Cunningham wrote: > > > > I saw the 2 suspends, 1 resume comment in another part of the threa= d, > > > > but don't believe a driver would be able to detect that 2 suspends > > > > and 1 resume call had been made - at least not without some non > > > > volatile ram. > > > > > > The extra suspend is just IMO a symptom of sloppiness, like a "here m= ay > > > be bugs" sign. Not necessarily an issue in its own right. > > > > > > In fact if you count carefully, it's three suspends and one resume:=20 > > > one suspend before calling swsusp_resume, one inside swsusp_resume -- > > > replaced by my patch -- and a correctly matched pair in the kernel > > > being resumed. > > > > That doesn't sound right. Let' see - where's this third one? > > I see your point ... device_suspend() and device_power_down() really > do the same thing, but to different sets of devices. A nastily deceptive > naming convention that I may want to fix someday. :) > So it's not quite fair counting those separately. Three suspend calls, > sure ... but only two per device. > > > > Also, about non-volatile RAM. Not necessary ... the device hardware > > > holds all the relevant state. The problem is that swsusp is now > > > trashing it with those suspend calls before resuming the real kernel.= =20 > > > On the plus side, we already have code being used to resolve the > > > identical issue for kexec(), and all my patch does is to use it. > > > > If devices really do get powered down, then they won't retain the state. > > If they don't actually powerdown, then I see your point. > > While the system is restarting into the snapshot, there's no powerdown. > (Because device_power_down doesn't actually power down devices.) Q.E.D. I thought that at least some devices might go D3cold, or is it always hot? = I'm=20 perfectly happy to admit being an ignoramus here - I'm just beginning to wo= rk=20 on drivers, so still have a lot to learn. Regards, Nigel =2D-=20 See our web page for Howtos, FAQs, the Wiki and mailing list info. http://www.suspend2.net IRC: #suspend2 on Freenode --nextPart29389695.nQdGM9HlHt Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBETuyYN0y+n1M3mo0RAu4YAKC47ocNxQ0GwhmrRyV5fknbPPixMwCeIO9H Hizj5eySpuoZ7aBH9z3Uc+o= =PkVo -----END PGP SIGNATURE----- --nextPart29389695.nQdGM9HlHt-- ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel