From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Schocher Subject: Re: ata, pcmcia: problem with irq and ata_dev_read_id() Date: Mon, 26 Jul 2010 14:59:16 +0200 Message-ID: <4C4D86A4.2040500@denx.de> References: <4C034FAE.9090605@denx.de> <4C044C8F.8050406@gmail.com> <4C2833B2.3040209@denx.de> <4C2DFF43.6050502@gmail.com> <4C319741.3060602@denx.de> <4C319D31.60705@gmail.com> <4C31A519.7030806@denx.de> <4C31A6DF.9080109@gmail.com> Reply-To: hs@denx.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7BIT Return-path: Received: from a.relay.invitel.net ([62.77.203.3]:46648 "EHLO a.relay.invitel.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752691Ab0GZM7X (ORCPT ); Mon, 26 Jul 2010 08:59:23 -0400 In-reply-to: <4C31A6DF.9080109@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Robert Hancock , Jeff Garzik , linux-ide@vger.kernel.org Hello Tejun, Tejun Heo wrote: > On 07/05/2010 11:25 AM, Heiko Schocher wrote: >>> Yeah, that's the new polling code kicking in. If the IRQ problem >>> doesn't persiste (which should be the case here), polling will step >>> down after a while and everything will return to normal. If you keep >>> the system running more than ten minutes and use the CF device, does >>> the kernel complain anymore? >> No, I can use the CF while kernel is in polling mode, also if the >> kernel switched back to irq mode: >> >> Log, direct after kernel is up: >> > .. >> 25: 9 MPC8XX SIU Level pata_pcmcia >> 26: 10000 MPC8XX SIU Level pata_pcmcia > ... >> No irq is used. >> >> -bash-3.2# dmesg >> [...] >> Freeing unused kernel memory: 132k init >> IRQ 26: spurious polling finished, reenabling IRQ >> -bash-3.2# >> >> Now it is back in irq mode: >> >> -bash-3.2# cat /proc/uptime >> 419.65 370.56 >> -bash-3.2# >> > ... >> 25: 9 MPC8XX SIU Level pata_pcmcia >> 26: 10033 MPC8XX SIU Level pata_pcmcia > > Cool, so it works as expected. With the new lost/spurious IRQ > handling in place, removing TFLAG_POLLING from read_id for all > controllers shouldn't cause much problem. However, the CF device is a > pretty rare corner case and spurious IRQ handling can deal with it > without too much problem, so leaving things as it is is probably > better. Hmm.. I am not sure if "leaving things as it is" is the better way, because this behaviour comes every time, I insert a card! And with my patch I can prevent this behaviour ... > Thanks for testing. Thanks for your comments! bye Heiko -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany