From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH] Smartreflex: Avoid unnecessary spam Date: Wed, 09 Dec 2009 15:51:24 -0800 Message-ID: <87d42nso3n.fsf@deeprootsystems.com> References: <1260281775-30361-1-git-send-email-tero.kristo@nokia.com> <87y6lbsprl.fsf@deeprootsystems.com> <20091209232309.GA9514@nokia.com> <4B2036F8.1090301@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-gx0-f212.google.com ([209.85.217.212]:60920 "EHLO mail-gx0-f212.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758801AbZLIXvV (ORCPT ); Wed, 9 Dec 2009 18:51:21 -0500 Received: by gxk4 with SMTP id 4so11729858gxk.8 for ; Wed, 09 Dec 2009 15:51:27 -0800 (PST) In-Reply-To: <4B2036F8.1090301@ti.com> (Nishanth Menon's message of "Wed\, 9 Dec 2009 17\:47\:04 -0600") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Nishanth Menon Cc: "felipe.balbi@nokia.com" , "Kristo Tero (Nokia-D/Tampere)" , "linux-omap@vger.kernel.org" Nishanth Menon writes: > Felipe Balbi had written, on 12/09/2009 05:23 PM, the following: >> On Thu, Dec 10, 2009 at 12:15:26AM +0100, ext Kevin Hilman wrote: >>> Tero Kristo writes: >>> >>>> From: Tero Kristo >>>> >>>> Current warning messages will be constantly printed out during normal operation >>>> if smartreflex autocompensation is disabled. >>>> >>>> Signed-off-by: Tero Kristo >>> Agreed that these warnings are spam, but I think they should be >>> replaced by some one-time warning so at least there's a hint someplace >>> that SR is not actually being done on a platfrom. >> >> well, there's printk_once() >> >> include/linux/kernel.h: >> >> 250 /* 251 * Print a one-time message (analogous to >> WARN_ONCE() et al): >> 252 */ 253 #define printk_once(x...) ({ >> \ >> 254 static bool __print_once = true; \ >> 255 \ >> 256 if (__print_once) { \ >> 257 __print_once = false; \ >> 258 printk(x); \ >> 259 } \ >> 260 }) >> >> and WARN_ONCE() >> >> include/asm-generic/bug.h: >> >> 125 #define WARN_ONCE(condition, format...) ({ \ >> 126 static int __warned; \ >> 127 int __ret_warn_once = !!(condition); \ >> 128 \ >> 129 if (unlikely(__ret_warn_once)) \ >> 130 if (WARN(!__warned, format)) \ >> 131 __warned = 1; \ >> 132 unlikely(__ret_warn_once); \ >> 133 }) >> >> I guess printk_once() is better. >> > But what is the point in having it? > situation 1: > sr_start_vddautocomap() gets called for starting AVS while dvfs. The > spam message just warns user that autocomp is not set when OPP change > happens. > > case 1 against printing it: > If the user had disabled vddautocomp, then the warnings have no > rational in warning the user which he/she already knows about. > > case 2 against printing it using printk_once: > situation x: > step 1: autocomp disabled, dvfs transitions -> printk_once will print > only once. > step 2: autocomp enabled, dvfs transitions - no prints. > step 3: autocomp disabled, dvfs - we wont see prints :( > Agreed, we could have an equivalent implementation using a static bool > instead of using printk_once .. still a nuisance message which does > not provide additional info.. other than adding a latency overhead. > > situation 2: > when attempting to enable SR when nvalues are not present (e.g. on > 3530/3430 es3.0).. here the return value should be used and is more > informative and usable from a application perspective.. > > just my 2 cents.. OK, I'm sold. Applying Tero's original patch. Kevin