From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [SCSI] fix media change events for polled devices Date: Fri, 21 Mar 2008 16:36:32 -0400 Message-ID: <47E41C50.4020406@garzik.org> References: <200803211559.m2LFxPi6017869@hera.kernel.org> <47E3EC67.4050404@garzik.org> <1206128662.2961.37.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:58532 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755215AbYCUUgg (ORCPT ); Fri, 21 Mar 2008 16:36:36 -0400 In-Reply-To: <1206128662.2961.37.camel@localhost.localdomain> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Linux Kernel Mailing List , Linus Torvalds , Kay Sievers , Andrew Morton , linux-scsi@vger.kernel.org James Bottomley wrote: > On Fri, 2008-03-21 at 13:12 -0400, Jeff Garzik wrote: >> Linux Kernel Mailing List wrote: >>> [SCSI] fix media change events for polled devices >>> >>> Commit: >>> a341cd0f (SCSI: add asynchronous event notification API) >>> breaks: >>> 285e9670 (sr,sd: send media state change modification events) >>> by introducing an event filter, which is removed here, to make >>> events, we are depending on, happen again. >> >> By simply reading the code history, it is trivial to verify that this >> description is false: >> >> Commit 285e9670 depends on a341cd0f, so by definition it is 285e9670 -- >> or rather the incomplete update of your original patch that resulted in >> 285e9670 -- that is broken. >> >> Since commit 285e9670 is broken, you fixed the wrong thing. >> >> Furthermore, you broke a userspace interface that was introduced by >> a341cd0f, by removing the event filter controlled by userspace. > >> Did anyone bother to read any code at all? > > Yes, I did. The userspace interface has never worked as a writeable > attribute because it's read only (as Kay has pointed out several times). > Based on that, I just #if'd out the filter code to get polled media > events working again. It has a show attribute and was obviously intended as a writable interface (and I should know, I wrote it). > The filter can be put back with a better discriminator for 2.6.26 > >> When 285e9670 was updated for the scsi_evt_* interface, it should have >> initialized the supported_events mask. > > That would break HAL ... it's using the presence of the media_event flag > in the variable to indicate it doesn't need to poll. We need two flags, > one for polling and one for AN. Oh for pete's sake. How hard is it to create a second bit _and_ keep the existing AN featureset working? _YOU_ are the one that broke this stuff in the first place, can you please take two seconds to fix it without breaking other stuff? Jeff