Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750980AbWHPHdg (ORCPT ); Wed, 16 Aug 2006 03:33:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750984AbWHPHdg (ORCPT ); Wed, 16 Aug 2006 03:33:36 -0400 Received: from main.gmane.org ([80.91.229.2]:7311 "EHLO ciao.gmane.org") by vger.kernel.org with ESMTP id S1750979AbWHPHdg (ORCPT ); Wed, 16 Aug 2006 03:33:36 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Giuseppe Bilotta Subject: Re: Polling for battery stauts and lost keypresses Date: Wed, 16 Aug 2006 09:31:48 +0200 Message-ID: References: <200608141038.04746.gene.heskett@verizon.net> <20060814152000.GA19065@rhlx01.fht-esslingen.de> <20060814155437.GA801@rhlx01.fht-esslingen.de> <1q38ghnxvrliv$.zzgutgu0exkm$.dlg@40tude.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: host-84-220-198-158.cust-adsl.tiscali.it User-Agent: 40tude_Dialog/2.0.15.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2552 Lines: 53 On Mon, 14 Aug 2006 16:17:01 -0400, Dmitry Torokhov wrote: > On 8/14/06, Giuseppe Bilotta wrote: >> On Mon, 14 Aug 2006 12:06:06 -0400, Dmitry Torokhov wrote: >> >>> On many laptops (including mine) polling battery takes a loooong time >>> and is done in SMI mode in BIOS causing lost keypresses, jerky mouse >>> etc. It is pretty common problem. I think I have my ACPI client >>> refreshing every 3 minutes. >> >> BTW, polling battery status takes a lot on a Dell Inspiron 8200 too, >> and all keypresses and mouse movements (and I think even network >> IRQs?) are totally *dead* while polling. >> >> However, The Other OS(tm) *seems* to do it right enough to have no >> noticeable keypress losses, even when updating the battery status. Is >> it using different system calls, or what? >> > > I am not sure, but there are many things that may affect it: > > 1. Battry attributes are divided into 2 groups - static (i think they > go into /proc/acpi/battery//info and dynamic > (/proc/acpi/batetry/state). Static attributes take really long time to > pull and they do not change so it may wery well be they are polled one > at startup. Dynamic attributes are cheaper to poll and even then OS > may cache access or limit rate. Well, this would explain why Linux freezes while polling only if Linux polls for the slow, static ones just as much as it does for the dynamic ones ... > 2. Quite often there are OEM drivers that are tweaked to a specific > hardware and involve hardware-specific hacks. If I remember correctly (damn, I can't find a way to do a search on the LKML archives ...) there was someone working on Dell stuff, at least as far as fans and thermal sensors were concerned (based on the code from Massimo Dal Zotto) to integrate them with the kernel sensors framework. However, some of those patches where NACKed by someone from Dell because they were sort of "guessy" about the addresses to poke around to get the information, instead of using the data provided by the BIOS on where to look for them ... however, there hasn't been any news about that that stuff since ... -- Giuseppe "Oblomov" Bilotta "Da grande lotter? per la pace" "A me me la compra il mio babbo" (Altan) ("When I grow up, I will fight for peace" "I'll have my daddy buy it for me") - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/