From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH V1 17/29] xen/arm: Mark each device used by Xen as disabled in DOM0 FDT Date: Mon, 09 Sep 2013 22:53:12 +0100 Message-ID: <522E4348.5060403@linaro.org> References: <1377701263-3319-1-git-send-email-julien.grall@linaro.org> <1377701263-3319-18-git-send-email-julien.grall@linaro.org> <1378726620.19967.70.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1378726620.19967.70.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: stefano.stabellini@eu.citrix.com, andre.przywara@linaro.org, patches@linaro.org, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 09/09/2013 12:37 PM, Ian Campbell wrote: > On Wed, 2013-08-28 at 15:47 +0100, Julien Grall wrote: >> When a device has a property status with disabled inside, Linux will not use >> the device. > > Do we not filter such devices out already? We only filter gic/timer node. All the others nodes used by Xen, for instance the serial device, will be marked by status = "disabled". > Or did the previous patch remove that functionality? In which case is > there a bisection hazard here? AFAIK, there is no bisection hazard with the current order of this patch series. > > Why is it preferred to leave the device with disabled in it instead of > removing it? (Can this go in the changelog please) > I think I've asked before, but is the handling of status = disabled > generic and therefore reliable? I let this patch because I didn't implement all the fake nodes in the previous patch series. In another hand, I'm not sure how Linux will react if there is a missing node and it should cope with status = "disabled" with most of nodes. I will give a try and see if I can remove completely nodes used by Xen. Except, of course, gic and timer nodes which are recreated later. >> >> Signed-off-by: Julien Grall >> --- >> xen/arch/arm/domain_build.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c >> index 76decf4..d56bc70a 100644 >> --- a/xen/arch/arm/domain_build.c >> +++ b/xen/arch/arm/domain_build.c >> @@ -208,6 +208,14 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo, >> return res; >> } >> >> + /* Disable all devices used by Xen */ >> + if ( dt_device_used_by(np) == DOMID_XEN ) >> + { >> + res = fdt_property(kinfo->fdt, "status", "disabled", 8 + 1); >> + if ( res ) >> + return res; >> + } >> + >> /* >> * XXX should populate /chosen/linux,initrd-{start,end} here if we >> * have module[2] > > -- Julien Grall