Re: [PATCH] libata-acpi: add back ACPI based hotplug functionality

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Wednesday, June 26, 2013 09:43:09 AM Aaron Lu wrote:
> On 06/24/2013 08:43 PM, Rafael J. Wysocki wrote:
> > From: Aaron Lu <aaron.lu@intel.com>
> > 
> > Commit 30dcf76acc69 "libata: migrate ACPI code over to new bindings"
> > mistakenly dropped the code to register hotplug notificaion handler
> > for ATA port/devices, causing regression for people using ATA bay,
> > as kernel bug #59871 shows.
> > 
> > Fix this by adding back the hotplug notification handler registration
> > code.  Since this code has to be run once and notification needs to
> > be installed on every ATA port/devices handle no matter if there is
> > actual device attached, we can't do this in binding time for ATA
> > device ACPI handle, as the binding only occurs when a SCSI device is
> > created, i.e. there is device attached.  So introduce the
> > ata_acpi_hotplug_init() function to loop scan all ATA ACPI handles
> > and if it is available, install the notificaion handler for it during
> > ATA init time.
> > 
> > With the ATA ACPI handle binding to SCSI device tree, it is possible
> > now that when the SCSI hotplug work removes the SCSI device, the ACPI
> > unbind function will find that the corresponding ACPI device has
> > already been deleted by dock driver, causing a scaring message like:
> > [  128.263966] scsi 4:0:0:0: Oops, 'acpi_handle' corrupt
> > Fix this by waiting for SCSI hotplug task finish in our notificaion
> > handler, so that the removal of ACPI device done in ACPI unbind
> > function triggered by the removal of SCSI device is run earlier when
> > ACPI device is still available.
> > 
> > [rjw: Rebased]
> > References: https://bugzilla.kernel.org/show_bug.cgi?id=59871
> > Reported-bisected-and-tested-by: Dirk Griesbach <spamthis@freenet.de>
> > Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> 
> Sorry for replying late, I forgot to CC stable here.
> Hopefully it's not too late.

I've added a CC to -stable to the commit log.

Thanks,
Rafael


> > ---
> > 
> > Hi Tejun,
> > 
> > If I'm not overlooking any hidden twists, it should be safe to add this
> > patch on top of the following three that I'm going to push for 3.10
> > in a couple of days (unless 3.10 is released first):
> > 
> > https://patchwork.kernel.org/patch/2766491/
> > https://patchwork.kernel.org/patch/2766501/
> > https://patchwork.kernel.org/patch/2768521/
> > 
> > May I add the $subject patch to that series and push along with it?
> > 
> > Rafael
> > 
> > ---
> >  drivers/ata/libata-acpi.c |   37 ++++++++++++++++++++++++++++++++++++-
> >  drivers/ata/libata-core.c |    2 ++
> >  drivers/ata/libata.h      |    2 ++
> >  3 files changed, 40 insertions(+), 1 deletion(-)
> > 
> > Index: linux-pm/drivers/ata/libata-acpi.c
> > ===================================================================
> > --- linux-pm.orig/drivers/ata/libata-acpi.c
> > +++ linux-pm/drivers/ata/libata-acpi.c
> > @@ -156,8 +156,10 @@ static void ata_acpi_handle_hotplug(stru
> >  
> >  	spin_unlock_irqrestore(ap->lock, flags);
> >  
> > -	if (wait)
> > +	if (wait) {
> >  		ata_port_wait_eh(ap);
> > +		flush_work(&ap->hotplug_task.work);
> > +	}
> >  }
> >  
> >  static void ata_acpi_dev_notify_dock(acpi_handle handle, u32 event, void *data)
> > @@ -214,6 +216,39 @@ static const struct acpi_dock_ops ata_ac
> >  	.uevent = ata_acpi_ap_uevent,
> >  };
> >  
> > +void ata_acpi_hotplug_init(struct ata_host *host)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < host->n_ports; i++) {
> > +		struct ata_port *ap = host->ports[i];
> > +		acpi_handle handle;
> > +		struct ata_device *dev;
> > +
> > +		if (!ap)
> > +			continue;
> > +
> > +		handle = ata_ap_acpi_handle(ap);
> > +		if (handle) {
> > +			/* we might be on a docking station */
> > +			register_hotplug_dock_device(handle,
> > +						     &ata_acpi_ap_dock_ops, ap,
> > +						     NULL, NULL);
> > +		}
> > +
> > +		ata_for_each_dev(dev, &ap->link, ALL) {
> > +			handle = ata_dev_acpi_handle(dev);
> > +			if (!handle)
> > +				continue;
> > +
> > +			/* we might be on a docking station */
> > +			register_hotplug_dock_device(handle,
> > +						     &ata_acpi_dev_dock_ops,
> > +						     dev, NULL, NULL);
> > +		}
> > +	}
> > +}
> > +
> >  /**
> >   * ata_acpi_dissociate - dissociate ATA host from ACPI objects
> >   * @host: target ATA host
> > Index: linux-pm/drivers/ata/libata-core.c
> > ===================================================================
> > --- linux-pm.orig/drivers/ata/libata-core.c
> > +++ linux-pm/drivers/ata/libata-core.c
> > @@ -6148,6 +6148,8 @@ int ata_host_register(struct ata_host *h
> >  	if (rc)
> >  		goto err_tadd;
> >  
> > +	ata_acpi_hotplug_init(host);
> > +
> >  	/* set cable, sata_spd_limit and report */
> >  	for (i = 0; i < host->n_ports; i++) {
> >  		struct ata_port *ap = host->ports[i];
> > Index: linux-pm/drivers/ata/libata.h
> > ===================================================================
> > --- linux-pm.orig/drivers/ata/libata.h
> > +++ linux-pm/drivers/ata/libata.h
> > @@ -122,6 +122,7 @@ extern int ata_acpi_register(void);
> >  extern void ata_acpi_unregister(void);
> >  extern void ata_acpi_bind(struct ata_device *dev);
> >  extern void ata_acpi_unbind(struct ata_device *dev);
> > +extern void ata_acpi_hotplug_init(struct ata_host *host);
> >  #else
> >  static inline void ata_acpi_dissociate(struct ata_host *host) { }
> >  static inline int ata_acpi_on_suspend(struct ata_port *ap) { return 0; }
> > @@ -134,6 +135,7 @@ static inline int ata_acpi_register(void
> >  static inline void ata_acpi_unregister(void) { }
> >  static inline void ata_acpi_bind(struct ata_device *dev) { }
> >  static inline void ata_acpi_unbind(struct ata_device *dev) { }
> > +static inline void ata_acpi_hotplug_init(struct ata_host *host) {}
> >  #endif
> >  
> >  /* libata-scsi.c */
> > 
> > --
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> > 
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.