Re: [Xen-devel] Problems when using latest git tree to boot xen on OMAP5

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2013-10-07 at 17:58 +0800, Chen Baozi wrote:
> 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 <baozich@xxxxxxxxx> 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.

I was grepping for mmc@480d1 not mmc4 so I missed this.

> Anyway, I'll see what exactly happened in the dom0 kernel dealing with
> those "disabled" regions.

Thanks.
Ian.

> 
> 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.
> > 
> > 



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel