Re: [patch 2/3] libata: expose AN support to user space via sysfs

From: Tejun Heo
Date: Wed Mar 28 2007 - 22:08:08 EST


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 <kristen.c.accardi@xxxxxxxxx>


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.

Thanks.

--
tejun
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