[patch 0/7] Asynchronous Notification for ATAPI devices (v2) - resend

[patch 0/7] Asynchronous Notification for ATAPI devices (v2) - resend

[Kristen Carlson Accardi]

This patch series implements Asynchronous Notification (AN) for SATA
ATAPI devices as defined in SATA 2.5 and AHCI 1.1 and higher.  Drives
which support this feature will send a notification when new media is
inserted and removed, preventing the need for user space to poll for
new media.  This support is exposed to user space via a flag that will
be set in /sys/block/sr*/capability_flags.  If the flag is set, user
space can disable polling for the new media, and the genhd driver will
send a KOBJ_CHANGE event with the envp set to MEDIA_CHANGE_EVENT=1.

Note that this patch only implements support for directly attached
drives - AN with drives attached to a port multiplier requires 
additional changes.

Thanks!
Kristen

-- 
-- 

Re: [patch 0/7] Asynchronous Notification for ATAPI devices (v2) - resend

[James Bottomley]

On Fri, 2007-05-04 at 11:12 -0700, Kristen Carlson Accardi wrote:
> This patch series implements Asynchronous Notification (AN) for SATA
> ATAPI devices as defined in SATA 2.5 and AHCI 1.1 and higher.  Drives
> which support this feature will send a notification when new media is
> inserted and removed, preventing the need for user space to poll for
> new media.  This support is exposed to user space via a flag that will
> be set in /sys/block/sr*/capability_flags.  If the flag is set, user
> space can disable polling for the new media, and the genhd driver will
> send a KOBJ_CHANGE event with the envp set to MEDIA_CHANGE_EVENT=1.
> 
> Note that this patch only implements support for directly attached
> drives - AN with drives attached to a port multiplier requires 
> additional changes.

I seem to remember when this came up before, the observation was made
that AENs occur for many more things than simple media change notices,
so we should probably have a more generic AEN handling mechanism.  Is
there any plan to move in this direction

James

Re: [patch 0/7] Asynchronous Notification for ATAPI devices (v2) - resend

[Kristen Carlson Accardi]

On Fri, 04 May 2007 15:30:03 -0500
James Bottomley <James.Bottomley@SteelEye.com> wrote:

> On Fri, 2007-05-04 at 11:12 -0700, Kristen Carlson Accardi wrote:
> > This patch series implements Asynchronous Notification (AN) for SATA
> > ATAPI devices as defined in SATA 2.5 and AHCI 1.1 and higher.  Drives
> > which support this feature will send a notification when new media is
> > inserted and removed, preventing the need for user space to poll for
> > new media.  This support is exposed to user space via a flag that will
> > be set in /sys/block/sr*/capability_flags.  If the flag is set, user
> > space can disable polling for the new media, and the genhd driver will
> > send a KOBJ_CHANGE event with the envp set to MEDIA_CHANGE_EVENT=1.
> > 
> > Note that this patch only implements support for directly attached
> > drives - AN with drives attached to a port multiplier requires 
> > additional changes.
> 
> I seem to remember when this came up before, the observation was made
> that AENs occur for many more things than simple media change notices,
> so we should probably have a more generic AEN handling mechanism.  Is
> there any plan to move in this direction
> 
> James
> 
In this implementation, we use kobject_uevent_env (vs. just 
kobject_uevent in the original implementation) to send a KOBJ_CHANGE
with the enviroment value of MEDIA_CHANGE=1.  For other asynchronous
events, you could still use KOBJ_CHANGE with a different env value.

Re: [patch 0/7] Asynchronous Notification for ATAPI devices (v2) - resend

[Tejun Heo]

Kristen Carlson Accardi wrote:
> This patch series implements Asynchronous Notification (AN) for SATA
> ATAPI devices as defined in SATA 2.5 and AHCI 1.1 and higher.  Drives
> which support this feature will send a notification when new media is
> inserted and removed, preventing the need for user space to poll for
> new media.  This support is exposed to user space via a flag that will
> be set in /sys/block/sr*/capability_flags.  If the flag is set, user
> space can disable polling for the new media, and the genhd driver will
> send a KOBJ_CHANGE event with the envp set to MEDIA_CHANGE_EVENT=1.
> 
> Note that this patch only implements support for directly attached
> drives - AN with drives attached to a port multiplier requires 
> additional changes.

No objection from me.  BTW, you're not setting ATA_FLAG_AN anywhere in
the patch series, will that be a separate patch?

-- 
tejun

Re: [patch 0/7] Asynchronous Notification for ATAPI devices (v2) - resend

[Kristen Carlson Accardi]

On Sun, 06 May 2007 12:15:34 +0200
Tejun Heo <htejun@gmail.com> wrote:

> Kristen Carlson Accardi wrote:
> > This patch series implements Asynchronous Notification (AN) for SATA
> > ATAPI devices as defined in SATA 2.5 and AHCI 1.1 and higher.  Drives
> > which support this feature will send a notification when new media is
> > inserted and removed, preventing the need for user space to poll for
> > new media.  This support is exposed to user space via a flag that will
> > be set in /sys/block/sr*/capability_flags.  If the flag is set, user
> > space can disable polling for the new media, and the genhd driver will
> > send a KOBJ_CHANGE event with the envp set to MEDIA_CHANGE_EVENT=1.
> > 
> > Note that this patch only implements support for directly attached
> > drives - AN with drives attached to a port multiplier requires 
> > additional changes.
> 
> No objection from me.  BTW, you're not setting ATA_FLAG_AN anywhere in
> the patch series, will that be a separate patch?
> 
> -- 
> tejun
> 

Yes - unfortunately I realized I'd forgotten to add that file to my
quilt patch about 5 minutes after I sent it :).  I thought if there were
no other revisions to this patch, I'd just send a separate one, otherwise
I'd incorporate it into the next version.