From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Some questions about new EH in libata Date: Wed, 30 Aug 2006 01:00:26 +0900 Message-ID: <44F4649A.80405@gmail.com> References: <8202f4270608212154k787f63a1k15ed3dcfff0624c2@mail.gmail.com> <44EA91A8.5090309@gmail.com> <8202f4270608281751v7cddfdddo28ba1b86eb43e60f@mail.gmail.com> <44F3A384.4080505@gmail.com> <8202f4270608290851u20ec2eb5j2fd7e509f617cf35@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from ug-out-1314.google.com ([66.249.92.175]:28996 "EHLO ug-out-1314.google.com") by vger.kernel.org with ESMTP id S1750761AbWH2QBW (ORCPT ); Tue, 29 Aug 2006 12:01:22 -0400 Received: by ug-out-1314.google.com with SMTP id m3so2023588ugc for ; Tue, 29 Aug 2006 09:01:21 -0700 (PDT) In-Reply-To: <8202f4270608290851u20ec2eb5j2fd7e509f617cf35@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Fajun Chen Cc: linux-ide@vger.kernel.org, jgarzik@pobox.com Fajun Chen wrote: > I assume that alt status register will be updated when pata/sata is > back online. So as an alternative and less invasive way, could I check > alt status register and start user scan only if device is ready on alt > status register? libata has ata_altstatus() function, is it available > to user space? If not, may I expose it? I'm looking for a way to check > device registers without side effects. You can't use alt status that way. Not all controllers have them and even those which do show different behaviors over hotplug/unplugs. Hmmm... maybe making userscan synchronous is the correct way to do it. I'll give it some thoughts. -- tejun