From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gra-lx1.iram.es (gra-lx1.iram.es [150.214.224.41]) by ozlabs.org (Postfix) with ESMTP id CE574679F6 for ; Mon, 15 May 2006 18:43:51 +1000 (EST) From: Gabriel Paubert Date: Mon, 15 May 2006 10:38:47 +0200 To: Benjamin Herrenschmidt Subject: Re: [PATCH] powerpc: Fix ide-pmac sysfs entry Message-ID: <20060515083847.GA5229@iram.es> References: <1147676318.21291.105.camel@localhost.localdomain> <20060515000810.487b834e.akpm@osdl.org> <1147677830.21291.114.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1147677830.21291.114.camel@localhost.localdomain> Cc: Andrew Morton , Pete Popov , B.Zolnierkiewicz@elka.pw.edu.pl, linuxppc-dev@ozlabs.org, paulus@samba.org, Alan Cox List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, May 15, 2006 at 05:23:50PM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2006-05-15 at 00:08 -0700, Andrew Morton wrote: > > Benjamin Herrenschmidt wrote: > > > > > > It looks like the generic ide code now wants ide_init_hwif_ports() to > > > set the parent struct device into the ide_hw structure (new field ?). > > > Without this, the mac ide code can cause the ide probing code to explode > > > in flames in sysfs registration due to what looks like a stale pointer > > > in there (happens when removing/re-inserting one of the hotswap media > > > bays on some laptops). > > > > > > > You don't sound very confident. > > Well, the problem is fixed with my change, I'd like to have Bart > confirmation that's its the right approach. It looks like it is but that > code is fairly intricated :) > > > afaict things went bad in October last year. hw_regs_t.dev was added here: > > > > http://www.kernel.org/git/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=26a940e21752e0de8f068f77dad606a7d1986937 > > > > but that only converted one driver to initialse ->dev. > > > > How come things didn't break then? Did some later change cause the > > problems? > > Well, for one, very few drivers cause ide_unregister nor rely on those > old mecanism... it seems that the way I initialize things at boot works > fine, it's when I unregister/re-register via the hotswap bay that things > go bunk. > > It's possible that it got broken back then and not noticed since ... or > another change actually made _use_ of that field... not sure, Bart might > confirm. The Mac laptops with those hotswap bays are fairly old and I > haven't tested for some time. I just did after getting user reports, and > users of old machines like that tend to use stable distro kernels which > tend to be fairly old... Actually I have one of these, and regularly use it and update the kernel to the latest git once or twice per month, but I typically have two batteries and have not swapped in the media bay under Linux for a long time. If you are interested, I could test the patch when I find some time (not today: my 8 year old son went to the hospital for an emergency last Thursday, he is cured now and should come out today). Regards, Gabriel