From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: SYSFS "errors" Date: Tue, 19 Feb 2013 12:43:46 +0100 Message-ID: <20130219114345.GA26623@pd.tnic> References: <20130218164638.7cb53baa@redhat.com> <20130218200542.GB20137@arwen.pp.htv.fi> <20130218184742.5a4c3c06@redhat.com> <20130218215434.GB16794@kroah.com> <20130218221306.GA21493@pd.tnic> <20130218222618.GA21818@kroah.com> <20130218224405.GB21493@pd.tnic> <20130219070310.2cadad7a@redhat.com> <20130219101121.GJ23197@arwen.pp.htv.fi> <20130219081149.46972f56@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.skyhub.de ([78.46.96.112]:36439 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932241Ab3BSLnu (ORCPT ); Tue, 19 Feb 2013 06:43:50 -0500 Content-Disposition: inline In-Reply-To: <20130219081149.46972f56@redhat.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Mauro Carvalho Chehab Cc: balbi@ti.com, Greg KH , Linux Kernel Mailing List , Steven Rostedt , Frederic Weisbecker , Ingo Molnar , JBottomley@parallels.com, linux-scsi@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org, Doug Thompson , linux-edac@vger.kernel.org, rjw@sisk.pl, linux-pm@vger.kernel.org On Tue, Feb 19, 2013 at 08:11:49AM -0300, Mauro Carvalho Chehab wrote: > > > I remember I saw some discussions about it in the past at bluesmo= ke ML, > > > saying that -ENODEV is the expected behavior when this is not sup= ported. > > >=20 > > > Changing from -ENODEV to "N/A" will break anything that would be = relying > > > on the previous behavior. So, I think that such change will for s= ure break > > > userspace. > > >=20 > > > If we're willing to change it, not creating the "sdram_scrub_rate= " sysfs=20 > > > node is less likely to affect userspace. This will break scripts which assume this file's presence implicitly. [ =E2=80=A6 ] > @@ -1017,6 +1010,14 @@ int edac_create_sysfs_mci_device(struct mem_ct= l_info *mci) > return err; > } > =20 > + if (mci->set_sdram_scrub_rate && mci->get_sdram_scrub_rate) { This will break cpc925_edac.c because it defines a ->get_sdram_scrub_rate but not a ->set_sdram_scrub_rate. I think a maybe better fix would be to figure out the sysfs file permissions based on the presence of the two functions and *then* add the attribute. This way, the only visible change to userspace is the corrected sysfs file permissions. --=20 Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --