Re: [PATCH] libata-acpi: add back ACPI based hotplug functionality
From: Rafael J. Wysocki
Date: Wed Jun 26 2013 - 08:40:18 EST
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@xxxxxxxxx>
> >
> > 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@xxxxxxxxxx>
> > Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
>
> 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.
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