From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 2/3] powerpc: Make default kexec/crash_kernel ops implicit From: Michael Ellerman To: avorontsov@ru.mvista.com In-Reply-To: <20081222001107.GA26630@oksana.dev.rtsoft.ru> References: <20081216162217.GA3885@oksana.dev.rtsoft.ru> <20081216162305.GB21749@oksana.dev.rtsoft.ru> <1229900922.8269.15.camel@localhost> <20081222001107.GA26630@oksana.dev.rtsoft.ru> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-jyCcD/18Qoml7NEZ587A" Date: Tue, 23 Dec 2008 11:15:21 +1100 Message-Id: <1229991321.9502.9.camel@localhost> Mime-Version: 1.0 Cc: Paul Mackerras , Milton Miller , linuxppc-dev@ozlabs.org Reply-To: michael@ellerman.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-jyCcD/18Qoml7NEZ587A Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2008-12-22 at 03:11 +0300, Anton Vorontsov wrote: > On Mon, Dec 22, 2008 at 10:08:42AM +1100, Michael Ellerman wrote: > > On Tue, 2008-12-16 at 19:23 +0300, Anton Vorontsov wrote: > > > This patch removes need for each platform to specify default kexec an= d > > > crash kernel ops, thus effectively adds a working kexec support for m= ost > > > boards. > > >=20 > > > Platforms that can't cope with default ops will explode in some weird > > > way (a hang or reboot is most likely), which means that the board's > > > kexec support should be fixed or blacklisted via dummy _prepare callb= ack > > > returning -ENOSYS. > >=20 > > But where is the patch to do this? >=20 > The -ENOSYS dummy callback is a last resort thing to do when nobody > cares or it's impossible to fix the Kexec on some board. We don't > have any such boards (yet). Yes we do, iseries, so at the very least we need a patch for that. > > The chance of kexec working on some random machine that's never been > > tested is pretty slim, every driver needs to be aware its hardware migh= t > > be in a weird state, >=20 > The boards setup isn't always static. The Kexec might work perfectly > well on a standalone board, but might hang with some weird PCI device > attached to it (think that it might need some PCI fixup on shutdown). >=20 > I think that a "Kexec tested to work on a particular board" term > just doesn't exist. It might work, but it might hang with other setup > on the *same* board. Sure, nothing is 100%, I'd just rather that someone has at least tried a kexec on the basic config and had it work. > But in practice the Kexec work on every 6xx board I have. And I have > pretty much of Freescale boards (almost all from the 83xx series), > and I don't think it's practical to add #ifdef CONFIG_KEXEC into the > every board file... OK in that case I'm OK with it. The Kconfig restricts it to only PPC64 or 6xx, so it's not enabled on _every_ platform. cheers --=20 Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person --=-jyCcD/18Qoml7NEZ587A Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAklQLZkACgkQdSjSd0sB4dIa6wCeIZdV/1b+XxSKz+u3N27hw51h hZcAnipMJXJUYNX2/J0uVlq3z/cUnWW7 =TOFi -----END PGP SIGNATURE----- --=-jyCcD/18Qoml7NEZ587A--