From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [patch 2/3] libata: expose AN support to user space via sysfs Date: Wed, 28 Mar 2007 22:19:53 -0400 Message-ID: <460B2249.4010200@pobox.com> References: <20070328230108.597741522@intel.com> <20070328164450.b89d5156.kristen.c.accardi@intel.com> <460B0539.9040103@pobox.com> <460B1F6B.5050108@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <460B1F6B.5050108@gmail.com> Sender: linux-scsi-owner@vger.kernel.org To: Tejun Heo Cc: Kristen Carlson Accardi , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-ide@vger.kernel.org, linux-scsi List-Id: linux-ide@vger.kernel.org Tejun Heo wrote: > Jeff Garzik wrote: >> Kristen Carlson Accardi wrote: >>> Allow user space to determine if an ATAPI device supports >>> async notification (AN) of media changes. This is done by >>> adding a new sysfs file "async_notification" to genhd. >>> If the file reads 1, then the device supports async notification. If >>> the file reads 0, it does not. A flag is set in the generic disk to >>> indicate whether >>> or not AN is supported. This flag is set by the SCSI >>> subsystem when it registers with add_disk. The SCSI >>> system gets information from libata on whether the >>> device supports AN during dev_configure. >>> Signed-off-by: Kristen Carlson Accardi >>> >> >> 3) I would make the contents of 'media_change_events' be a list of >> flags, rather than a boolean. Thus, when AN is present, >> media_change_events would return "AN\n". It would return "\n" (no >> flags) when AN is absent. This permits future expansion of this >> capabilities reporting variable. > > I'm not sure about this. AN is kind of specific term for ATA while > media change event is generic. So, I think the original approach is > okay. No matter how the actual thing is implemented, it's the same > media change event and as long as event delivery interface is the same, > upper layer shouldn't care about how it's done. AN is a generic concept that I feel will propagate elsewhere. Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. Jeff