From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH V2 07/33] xen/arm: Create a hierarchical device tree Date: Wed, 08 May 2013 16:15:29 +0100 Message-ID: <518A6C11.40606@linaro.org> References: <1368018689.26321.286.camel@zakaz.uk.xensource.com> <518A5470.40500@linaro.org> <1368020468.17285.2.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1368020468.17285.2.camel@zakaz.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 , "patches@linaro.org" , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 05/08/2013 02:41 PM, Ian Campbell wrote: > On Wed, 2013-05-08 at 14:34 +0100, Julien Grall wrote: >>> Which only leaves ones which are both? How many are these? I'm inclined >>> towards suggesting that if they are debug prints which are disabled by >>> default and require a recompile to enable then the person doing the >>> debugging can select whether they care about early or late messages by >>> #define-ing DEBUG or EARLY_DEBUG or both as required. >> >> We can't choose at compile time. Early printk function is in init code >> section. So at the end of boot the function will disappear. > > Oh, right. > > Perhaps something could be conditional on system_state = > SYS_STATE_active, this happens not long before we discard the initial > sections. I think it's too late. If we use early_printk until this stage, we will lose some usefull debug when early printk is disabled (ie most of the time). How about adding the missing system_state = SYS_STATE_boot just after console_init_preirq? Early printk will only be used when system_state == SYS_STATE_early_boot. >> Device tree function could be called after the end of the boot. For the >> moment it's not the case. >> >> The best solution would be: early_printk is directly handled in console >> as linux does. > > That does sound best. I will send a patch later for this. -- Julien