From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Baozi Subject: Re: Problems when using latest git tree to boot xen on OMAP5 Date: Mon, 07 Oct 2013 17:58:11 +0800 Message-ID: <525285B3.8010902@gmail.com> References: <936C837B-7005-4CE0-8265-7B7ACA7C78FD@gmail.com> <91879A6F-B459-4D10-A691-4A04915D82AA@gmail.com> <1381135195.21562.56.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1381135195.21562.56.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Grall Julien , List Xen Developer List-Id: xen-devel@lists.xenproject.org On 10/07/2013 04:39 PM, Ian Campbell wrote: > On Sun, 2013-10-06 at 22:21 +0800, Chen Baozi wrote: >> On Oct 4, 2013, at 10:11 PM, Chen Baozi wrote: >> >>> Hi Julien, >>> >>> Since Ian has merged most my OMAP5 patches, I decide to try to update my working tree to it today. However, it seems it doesn't work as expected. There mainly two kind of problems that I met: >>> >>> 1. It seems that xen no longer maps some of io memory regions described in dts. For example, the memory regions in "ocp" node of omap5.dtsi. >> >> I looked into the codes today. It is because of checking >> dt_device_is_available() before map_device(). Some node, for >> example /ocp/mmc@480d1000, is disabled in omap5-uevm.dts separately >> from omap5.dtsi where it is original defined. In this case, xen won't >> map its memory region for dom0. However, it seems dom0 kernel still >> accesses those regions. > >> I guess there would be a bug dealing with this situations? > > It is certainly a bug in the kernel if it is accessing something which > is disabled. It may also independently be a bug in the dts that this > devices is disabled. > > However in v3.12-rc4 I don't see mmc@480d1000 being disabled in > omap5-uevm.dts and I can't see anything in the history of that file > either. Where did your copy come from? I'm currently working on the "omap5-v3.11-rc3" branch from git://github.com/rogerq/linux.git, which contains a few necessary platform patches not upstreamed. In omap5-uevm.dts, there are lines like: 253 &mmc4 { 254 status = "disabled"; 255 }; 256 257 &mmc5 { 258 status = "disabled"; 259 }; the mmc4 refers to mmc@480d1000, which defines at omap5.dtsi: 417 mmc4: mmc@480d1000 { I checked Linus' mainline git tree. It is the same about disabled mmc4 in omap5-uevm.dts. And the change is introduced in commit 5dd18b0 of the mainline kernel. Anyway, I'll see what exactly happened in the dom0 kernel dealing with those "disabled" regions. Cheers, Baozi > > Hopefully we won't need a converse to the device blacklist, i.e. a > whitelist of disabled devices to pass through regardless of the DTS > enabled state. > > Ian. > >