Re: [PATCH]libata-acpi: add ACPI _PSx method

Shaohua Li
2007-09-21T01:33:34Z

On Thu, 2007-09-20 at 18:00 -0400, Jeff Garzik wrote:
> Shaohua Li wrote:
> > ACPI spec (ver 3.0a, p289) requires IDE power on/off executes ACPI _PSx
> > methods. As recently most PATA drivers use libata, this patch adds _PSx
> > method support in libata. ACPI spec doesn't mention if SATA requires the
> > same _PSx method, but executing _PSx for SATA should be ok I think.
> >
> > Signed-off-by: Shaohua Li <shaohua.li@intel.com>
>
> ahci and sata_sil24 directly power off components, so it seems quite
> unwise for "modern" SATA controllers.
>
> ISTR Tejun, when he cleaned up libata-acpi, finally figured out a good
> way to distinguish ACPI's idea of "IDE" -- which sometimes includes the
> legacy programming mode of SATA controllers, and a controller running a
> modern programming mode.
>
> Your best bet is to use a similar test when deciding when to execute
> _PSx. Or, you could simply be conservative and only do it for PATA.
>
> outside of those issues, the rest of the patch looks ok.
Then how about this one? I added a check in ata_acpi_set_state to skip
SATA device, assume this is what you are talking about.

Thanks,
Shaohua

---
drivers/ata/libata-acpi.c | 34 ++++++++++++++++++++++++++++++++++
drivers/ata/libata-eh.c | 3 +++
drivers/ata/libata.h | 2 ++
3 files changed, 39 insertions(+)

Index: linux/drivers/ata/libata-acpi.c
===================================================================
--- linux.orig/drivers/ata/libata-acpi.c 2007-09-14 10:28:25.000000000 +0800
+++ linux/drivers/ata/libata-acpi.c 2007-09-21 08:58:18.000000000 +0800
@@ -523,6 +523,40 @@ void ata_acpi_on_resume(struct ata_port
}

/**
+ * ata_acpi_set_state - set the port power state
+ * @ap: target ATA port
+ * @state: state, on/off
+ *
+ * This function executes the _PS0/_PS3 ACPI method to set the power state.
+ * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
+ */
+void ata_acpi_set_state(struct ata_port *ap, pm_message_t state)
+{
+ int max_devices = 1, i;
+
+ if (!ap->acpi_handle || (ap->flags & ATA_FLAG_ACPI_SATA))
+ return;
+
+ /* channel first and then drives for power on and verse versa for power off */
+ if (state.event == PM_EVENT_ON)
+ acpi_bus_set_power(ap->acpi_handle, ACPI_STATE_D0);
+
+ if (ap->flags & ATA_FLAG_SLAVE_POSS)
+ max_devices++;
+
+ for (i = 0; i < max_devices; ++i) {
+ struct ata_device *dev = &ap->device[i];
+
+ if (dev->acpi_handle)
+ acpi_bus_set_power(dev->acpi_handle,
+ state.event == PM_EVENT_ON ?
+ ACPI_STATE_D0: ACPI_STATE_D3);
+ }
+ if (state.event != PM_EVENT_ON)
+ acpi_bus_set_power(ap->acpi_handle, ACPI_STATE_D3);
+}
+
+/**
* ata_acpi_on_devcfg - ATA ACPI hook called on device donfiguration
* @dev: target ATA device
*
Index: linux/drivers/ata/libata-eh.c
===================================================================
--- linux.orig/drivers/ata/libata-eh.c 2007-09-14 10:28:25.000000000 +0800
+++ linux/drivers/ata/libata-eh.c 2007-09-21 08:56:40.000000000 +0800
@@ -2349,6 +2349,7 @@ static void ata_eh_handle_port_suspend(s
if (ap->ops->port_suspend)
rc = ap->ops->port_suspend(ap, ap->pm_mesg);

+ ata_acpi_set_state(ap, PMSG_SUSPEND);
out:
/* report result */
spin_lock_irqsave(ap->lock, flags);
@@ -2394,6 +2395,8 @@ static void ata_eh_handle_port_resume(st

WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));

+ ata_acpi_set_state(ap, PMSG_ON);
+
if (ap->ops->port_resume)
rc = ap->ops->port_resume(ap);

Index: linux/drivers/ata/libata.h
===================================================================
--- linux.orig/drivers/ata/libata.h 2007-09-14 10:28:25.000000000 +0800
+++ linux/drivers/ata/libata.h 2007-09-21 08:56:40.000000000 +0800
@@ -102,11 +102,13 @@ extern void ata_acpi_associate(struct at
extern int ata_acpi_on_suspend(struct ata_port *ap);
extern void ata_acpi_on_resume(struct ata_port *ap);
extern int ata_acpi_on_devcfg(struct ata_device *adev);
+extern void ata_acpi_set_state(struct ata_port *ap, pm_message_t state);
#else
static inline void ata_acpi_associate(struct ata_host *host) { }
static inline int ata_acpi_on_suspend(struct ata_port *ap) { return 0; }
static inline void ata_acpi_on_resume(struct ata_port *ap) { }
static inline int ata_acpi_on_devcfg(struct ata_device *adev) { return 0; }
+static inline void ata_acpi_set_state(struct ata_port *ap, pm_message_t state) { }
#endif

/* libata-scsi.c */