[PATCH] libata: reimplement controller-wide PM

Reimplement controller-wide PM.  ata_host_set_suspend/resume() are
defined to suspend and resume a host_set.  While suspended, EHs for
all ports in the host_set are pegged using ATA_FLAG_SUSPENDED and
frozen.

Because SCSI device hotplug is done asynchronously against the rest of
libata EH and the same mutex is used when adding new device, suspend
cannot wait for hotplug to complete.  So, if SCSI device hotplug is in
progress, suspend fails with -EBUSY.

In most cases, host_set resume is followed by device resume.  As each
resume operation requires a reset, a single host_set-wide resume
operation may result in multiple resets.  To avoid this, resume waits
upto 1 second giving PM to request resume for devices.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 5ac262608199..6cc497a2b6da 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -182,6 +182,7 @@ enum {
 
         ATA_PFLAG_FLUSH_PORT_TASK = (1 << 16), /* flush port task */
         ATA_PFLAG_SUSPENDED     = (1 << 17), /* port is suspended (power) */
+        ATA_PFLAG_PM_PENDING    = (1 << 18), /* PM operation pending */
 
         /* struct ata_queued_cmd flags */
         ATA_QCFLAG_ACTIVE       = (1 << 0), /* cmd not yet ack'd to scsi lyer */
@@ -549,6 +550,9 @@ struct ata_port {
         struct list_head        eh_done_q;
         wait_queue_head_t       eh_wait_q;
 
+        pm_message_t            pm_mesg;
+        int                     *pm_result;
+
         void                    *private_data;
 
         u8                      sector_buf[ATA_SECT_SIZE]; /* owned by EH */
@@ -603,6 +607,9 @@ struct ata_port_operations {
         void (*scr_write) (struct ata_port *ap, unsigned int sc_reg,
                            u32 val);
 
+        int (*port_suspend) (struct ata_port *ap, pm_message_t mesg);
+        int (*port_resume) (struct ata_port *ap);
+
         int (*port_start) (struct ata_port *ap);
         void (*port_stop) (struct ata_port *ap);
 
@@ -667,6 +674,8 @@ extern void ata_std_ports(struct ata_ioports *ioaddr);
 extern int ata_pci_init_one (struct pci_dev *pdev, struct ata_port_info **port_info,
                              unsigned int n_ports);
 extern void ata_pci_remove_one (struct pci_dev *pdev);
+extern void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t state);
+extern void ata_pci_device_do_resume(struct pci_dev *pdev);
 extern int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t state);
 extern int ata_pci_device_resume(struct pci_dev *pdev);
 extern int ata_pci_clear_simplex(struct pci_dev *pdev);
@@ -687,6 +696,9 @@ extern int ata_port_online(struct ata_port *ap);
 extern int ata_port_offline(struct ata_port *ap);
 extern int ata_scsi_device_resume(struct scsi_device *);
 extern int ata_scsi_device_suspend(struct scsi_device *, pm_message_t state);
+extern int ata_host_set_suspend(struct ata_host_set *host_set,
+                                pm_message_t mesg);
+extern void ata_host_set_resume(struct ata_host_set *host_set);
 extern int ata_ratelimit(void);
 extern unsigned int ata_busy_sleep(struct ata_port *ap,
                                    unsigned long timeout_pat,