ZPODD Patches

index 5fc97d2..4d1a610 100644
@@ -45,6 +45,7 @@
 #include <linux/blkdev.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
 #include <asm/uaccess.h>
 
 #include <scsi/scsi.h>

@@ -146,7 +147,8 @@ static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
 	kref_get(&cd->kref);
 	if (scsi_device_get(cd->device))
 		goto out_put;
-	goto out;
+	if (!scsi_autopm_get_device(cd->device))
+		goto out;
 
  out_put:
 	kref_put(&cd->kref, sr_kref_release);

@@ -162,6 +164,7 @@ static void scsi_cd_put(struct scsi_cd *cd)
 
 	mutex_lock(&sr_ref_mutex);
 	kref_put(&cd->kref, sr_kref_release);
+	scsi_autopm_put_device(sdev);
 	scsi_device_put(sdev);
 	mutex_unlock(&sr_ref_mutex);
 }

@@ -211,7 +214,7 @@ static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 				    unsigned int clearing, int slot)
 {
 	struct scsi_cd *cd = cdi->handle;
-	bool last_present;
+	bool last_present = cd->media_present;
 	struct scsi_sense_hdr sshdr;
 	unsigned int events;
 	int ret;

@@ -220,6 +223,8 @@ static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 	if (CDSL_CURRENT != slot)
 		return 0;
 
+	scsi_autopm_get_device(cd->device);
+
 	events = sr_get_events(cd->device);
 	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
 

@@ -246,10 +251,9 @@ static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 	}
 
 	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
-		return events;
+		goto out;
 do_tur:
 	/* let's see whether the media is there with TUR */
-	last_present = cd->media_present;
 	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 
 	/*

@@ -270,7 +274,7 @@ do_tur:
 	}
 
 	if (cd->ignore_get_event)
-		return events;
+		goto out;
 
 	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
 	if (!cd->tur_changed) {

@@ -287,6 +291,18 @@ do_tur:
 	cd->tur_changed = false;
 	cd->get_event_changed = false;
 
+out:
+	/*
+	 * If there is no medium detected or the medium has been there
+	 * since last poll, try to suspend the device. Otherwise, keep
+	 * it active for one more poll interval so that if user space
+	 * application opens the block device, we can avoid a runtime
+	 * status change.
+	 */
+	pm_runtime_put_noidle(&cd->device->sdev_gendev);
+	if (!cd->media_present || last_present)
+		pm_runtime_suspend(&cd->device->sdev_gendev);
+
 	return events;
 }
 

@@ -718,6 +734,8 @@ static int sr_probe(struct device *dev)
 
 	sdev_printk(KERN_DEBUG, sdev,
 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
+	scsi_autopm_put_device(cd->device);
+
 	return 0;
 
 fail_put:

@@ -965,6 +983,8 @@ static int sr_remove(struct device *dev)
 {
 	struct scsi_cd *cd = dev_get_drvdata(dev);
 
+	scsi_autopm_get_device(cd->device);
+
 	blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
 	del_gendisk(cd->disk);
 

index 5b0ba3f..5a44604 100644
@@ -1059,6 +1059,8 @@ void ata_acpi_bind(struct ata_device *dev)
 
 void ata_acpi_unbind(struct ata_device *dev)
 {
+	if (zpodd_dev_enabled(dev))
+		zpodd_exit(dev);
 	ata_acpi_remove_pm_notifier(dev);
 	ata_acpi_unregister_power_resource(dev);
 }

index f46fbd3..97987e7 100644
@@ -2395,8 +2395,10 @@ int ata_dev_configure(struct ata_device *dev)
 			dma_dir_string = ", DMADIR";
 		}
 
-		if (ata_id_has_da(dev->id))
+		if (ata_id_has_da(dev->id)) {
 			dev->flags |= ATA_DFLAG_DA;
+			zpodd_init(dev);
+		}
 
 		/* print device info to dmesg */
 		if (ata_msg_drv(ap) && print_info)

124 lines not on this page · raw message

index 7148a58..8cb4372 100644
@@ -230,4 +230,18 @@ static inline void ata_sff_exit(void)
 { }
 #endif /* CONFIG_ATA_SFF */
 
+/* libata-zpodd.c */
+#ifdef CONFIG_SATA_ZPODD
+void zpodd_init(struct ata_device *dev);
+void zpodd_exit(struct ata_device *dev);
+static inline bool zpodd_dev_enabled(struct ata_device *dev)
+{
+	return dev->zpodd ? true : false;
+}
+#else /* CONFIG_SATA_ZPODD */
+static inline void zpodd_init(struct ata_device *dev) {}
+static inline void zpodd_exit(struct ata_device *dev) {}
+static inline bool zpodd_dev_enabled(struct ata_device *dev) { return false; }
+#endif /* CONFIG_SATA_ZPODD */
+
 #endif /* __LIBATA_H__ */

index 77eeeda..d550423 100644
@@ -619,6 +619,9 @@ struct ata_device {
 	union acpi_object	*gtf_cache;
 	unsigned int		gtf_filter;
 #endif
+#ifdef CONFIG_SATA_ZPODD
+	void			*zpodd;
+#endif
 	struct device		tdev;
 	/* n_sector is CLEAR_BEGIN, read comment above CLEAR_BEGIN */
 	u64			n_sectors;	/* size of device, if ATA */

index 898b866..bd17ad5 100644
@@ -908,5 +908,39 @@ struct mode_page_header {
 	__be16 desc_length;
 };
 
+/* removable medium feature descriptor */
+struct rm_feature_desc {
+	__be16 feature_code;
+#if defined(__BIG_ENDIAN_BITFIELD)
+	__u8 reserved1:2;
+	__u8 feature_version:4;
+	__u8 persistent:1;
+	__u8 curr:1;
+#elif defined(__LITTLE_ENDIAN_BITFIELD)
+	__u8 curr:1;
+	__u8 persistent:1;
+	__u8 feature_version:4;
+	__u8 reserved1:2;
+#endif
+	__u8 add_len;
+#if defined(__BIG_ENDIAN_BITFIELD)
+	__u8 mech_type:3;
+	__u8 load:1;
+	__u8 eject:1;
+	__u8 pvnt_jmpr:1;
+	__u8 dbml:1;
+	__u8 lock:1;
+#elif defined(__LITTLE_ENDIAN_BITFIELD)
+	__u8 lock:1;
+	__u8 dbml:1;
+	__u8 pvnt_jmpr:1;
+	__u8 eject:1;
+	__u8 load:1;
+	__u8 mech_type:3;
+#endif
+	__u8 reserved2;
+	__u8 reserved3;
+	__u8 reserved4;
+};
 
 #endif /* _UAPI_LINUX_CDROM_H */

index 5a44604..03ee60f 100644
@@ -970,57 +970,6 @@ void ata_acpi_on_disable(struct ata_device *dev)
 	ata_acpi_clear_gtf(dev);
 }
 
-static void ata_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
-{
-	struct ata_device *ata_dev = context;
-
-	if (event == ACPI_NOTIFY_DEVICE_WAKE && ata_dev &&
-			pm_runtime_suspended(&ata_dev->sdev->sdev_gendev))
-		scsi_autopm_get_device(ata_dev->sdev);
-}
-
-static void ata_acpi_add_pm_notifier(struct ata_device *dev)
-{
-	struct acpi_device *acpi_dev;
-	acpi_handle handle;
-	acpi_status status;
-
-	handle = ata_dev_acpi_handle(dev);
-	if (!handle)
-		return;
-
-	status = acpi_bus_get_device(handle, &acpi_dev);
-	if (ACPI_FAILURE(status))
-		return;
-
-	if (dev->sdev->can_power_off) {
-		acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
-			ata_acpi_wake_dev, dev);
-		device_set_run_wake(&dev->sdev->sdev_gendev, true);
-	}
-}
-
-static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
-{
-	struct acpi_device *acpi_dev;
-	acpi_handle handle;
-	acpi_status status;
-
-	handle = ata_dev_acpi_handle(dev);
-	if (!handle)
-		return;
-
-	status = acpi_bus_get_device(handle, &acpi_dev);
-	if (ACPI_FAILURE(status))
-		return;
-
-	if (dev->sdev->can_power_off) {
-		device_set_run_wake(&dev->sdev->sdev_gendev, false);
-		acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
-			ata_acpi_wake_dev);
-	}
-}
-
 static void ata_acpi_register_power_resource(struct ata_device *dev)
 {
 	struct scsi_device *sdev = dev->sdev;

@@ -1053,7 +1002,6 @@ static void ata_acpi_unregister_power_resource(struct ata_device *dev)
 
 void ata_acpi_bind(struct ata_device *dev)
 {
-	ata_acpi_add_pm_notifier(dev);
 	ata_acpi_register_power_resource(dev);
 }
 

@@ -1061,7 +1009,6 @@ void ata_acpi_unbind(struct ata_device *dev)
 {
 	if (zpodd_dev_enabled(dev))
 		zpodd_exit(dev);
-	ata_acpi_remove_pm_notifier(dev);
 	ata_acpi_unregister_power_resource(dev);
 }
 

@@ -1103,9 +1050,6 @@ static int ata_acpi_bind_device(struct ata_port *ap, struct scsi_device *sdev,
 				acpi_handle *handle)
 {
 	struct ata_device *ata_dev;
-	acpi_status status;
-	struct acpi_device *acpi_dev;
-	struct acpi_device_power_state *states;
 
 	if (ap->flags & ATA_FLAG_ACPI_SATA) {
 		if (!sata_pmp_attached(ap))

@@ -1122,21 +1066,6 @@ static int ata_acpi_bind_device(struct ata_port *ap, struct scsi_device *sdev,
 	if (!*handle)
 		return -ENODEV;
 
-	status = acpi_bus_get_device(*handle, &acpi_dev);
-	if (ACPI_FAILURE(status))
-		return 0;
-
-	/*
-	 * If firmware has _PS3 or _PR3 for this device,
-	 * and this ata ODD device support device attention,
-	 * it means this device can be powered off
-	 */
-	states = acpi_dev->power.states;
-	if ((states[ACPI_STATE_D3_HOT].flags.valid ||
-			states[ACPI_STATE_D3_COLD].flags.explicit_set) &&
-			ata_dev->flags & ATA_DFLAG_DA)
-		sdev->can_power_off = 1;
-
 	return 0;
 }
 

index f612036..3669eb4 100644
@@ -1,5 +1,7 @@
 #include <linux/libata.h>
 #include <linux/cdrom.h>
+#include <linux/pm_runtime.h>
+#include <scsi/scsi_device.h>
 
 #include "libata.h"
 

@@ -7,6 +9,9 @@ struct zpodd {
 	bool slot:1;
 	bool drawer:1;
 
+	/* The following bits are synchronized by PM core */
+	bool from_notify:1; /* resumed as a result of acpi notification */
+
 	struct ata_device *dev;
 };
 

@@ -90,6 +95,32 @@ static bool device_can_poweroff(struct ata_device *ata_dev)
 		return false;
 }
 
+static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)
+{
+	struct ata_device *ata_dev = context;
+	struct zpodd *zpodd = ata_dev->zpodd;
+	struct device *dev = &ata_dev->sdev->sdev_gendev;
+
+	if (event == ACPI_NOTIFY_DEVICE_WAKE && ata_dev &&
+			pm_runtime_suspended(dev)) {
+		zpodd->from_notify = true;
+		pm_runtime_resume(dev);
+	}
+}
+
+static void acpi_add_pm_notifier(struct ata_device *dev)
+{
+	acpi_handle handle = ata_dev_acpi_handle(dev);
+	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+				    zpodd_wake_dev, dev);
+}
+
+static void acpi_remove_pm_notifier(struct ata_device *dev)
+{
+	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->sdev->sdev_gendev);
+	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
+}
+
 void zpodd_init(struct ata_device *dev)
 {
 	int ret;

@@ -113,12 +144,14 @@ void zpodd_init(struct ata_device *dev)
 	else
 		zpodd->slot = true;
 
+	acpi_add_pm_notifier(dev);
 	zpodd->dev = dev;
 	dev->zpodd = zpodd;
 }
 
 void zpodd_exit(struct ata_device *dev)
 {
+	acpi_remove_pm_notifier(dev);
 	kfree(dev->zpodd);
 	dev->zpodd = NULL;
 }

index e60437c..b928892 100644
@@ -1591,7 +1591,7 @@ static int ata_eh_read_log_10h(struct ata_device *dev,
  *	RETURNS:
  *	0 on success, AC_ERR_* mask on failure.
  */
-static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
+unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
 {
 	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
 	struct ata_taskfile tf;

@@ -1624,7 +1624,7 @@ static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
  *	RETURNS:
  *	0 on success, AC_ERR_* mask on failure
  */
-static unsigned int atapi_eh_request_sense(struct ata_device *dev,
+unsigned int atapi_eh_request_sense(struct ata_device *dev,
 					   u8 *sense_buf, u8 dfl_sense_key)
 {
 	u8 cdb[ATAPI_CDB_LEN] =

@@ -4021,6 +4021,7 @@ static void ata_eh_handle_port_suspend(struct ata_port *ap)
 {
 	unsigned long flags;
 	int rc = 0;
+	struct ata_device *dev;
 
 	/* are we suspending? */
 	spin_lock_irqsave(ap->lock, flags);

@@ -4033,6 +4034,11 @@ static void ata_eh_handle_port_suspend(struct ata_port *ap)
 
 	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
 
+	ata_for_each_dev(dev, &ap->link, ENABLED) {
+		if (zpodd_dev_enabled(dev))
+			zpodd_on_suspend(dev);
+	}
+
 	/* tell ACPI we're suspending */
 	rc = ata_acpi_on_suspend(ap);
 	if (rc)

84 lines not on this page · raw message

index 8cb4372..f9235dc 100644
@@ -182,6 +182,9 @@ extern void ata_eh_finish(struct ata_port *ap);
 extern int ata_ering_map(struct ata_ering *ering,
 			 int (*map_fn)(struct ata_ering_entry *, void *),
 		  	 void *arg);
+extern unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key);
+extern unsigned int atapi_eh_request_sense(struct ata_device *dev,
+					   u8 *sense_buf, u8 dfl_sense_key);
 
 /* libata-pmp.c */
 #ifdef CONFIG_SATA_PMP

@@ -238,10 +241,12 @@ static inline bool zpodd_dev_enabled(struct ata_device *dev)
 {
 	return dev->zpodd ? true : false;
 }
+void zpodd_on_suspend(struct ata_device *dev);
 #else /* CONFIG_SATA_ZPODD */
 static inline void zpodd_init(struct ata_device *dev) {}
 static inline void zpodd_exit(struct ata_device *dev) {}
 static inline bool zpodd_dev_enabled(struct ata_device *dev) { return false; }
+static inline void zpodd_on_suspend(struct ata_device *dev) {}
 #endif /* CONFIG_SATA_ZPODD */
 
 #endif /* __LIBATA_H__ */

index 03ee60f..3a82177 100644
@@ -832,6 +832,24 @@ void ata_acpi_on_resume(struct ata_port *ap)
 	}
 }
 
+static int ata_acpi_choose_state(struct ata_device *dev)
+{
+	/* Always choose D3 for PATA devices */
+	if (!(dev->link->ap->flags & ATA_FLAG_ACPI_SATA))
+		return ACPI_STATE_D3;
+
+	if (zpodd_dev_enabled(dev)) {
+		if (zpodd_poweroff_ready(dev))
+			dev_pm_qos_update_request(&dev->pm_qos_req, 0);
+		else
+			dev_pm_qos_update_request(&dev->pm_qos_req,
+						  PM_QOS_FLAG_NO_POWER_OFF);
+	}
+
+	return acpi_pm_device_sleep_state(&dev->sdev->sdev_gendev,
+					  NULL, ACPI_STATE_D3_COLD);
+}
+
 /**
  * ata_acpi_set_state - set the port power state
  * @ap: target ATA port

@@ -858,17 +876,16 @@ void ata_acpi_set_state(struct ata_port *ap, pm_message_t state)
 			continue;
 
 		if (state.event != PM_EVENT_ON) {
-			acpi_state = acpi_pm_device_sleep_state(
-				&dev->sdev->sdev_gendev, NULL, ACPI_STATE_D3);
-			if (acpi_state > 0)
+			acpi_state = ata_acpi_choose_state(dev);
+			if (acpi_state > 0) {
 				acpi_bus_set_power(handle, acpi_state);
-			/* TBD: need to check if it's runtime pm request */
-			acpi_pm_device_run_wake(
-				&dev->sdev->sdev_gendev, true);
+				if (zpodd_dev_enabled(dev) &&
+				    acpi_state == ACPI_STATE_D3_COLD)
+					zpodd_post_poweroff(dev);
+			}
 		} else {
-			/* Ditto */
-			acpi_pm_device_run_wake(
-				&dev->sdev->sdev_gendev, false);
+			if (zpodd_dev_enabled(dev))
+				zpodd_pre_poweron(dev);
 			acpi_bus_set_power(handle, ACPI_STATE_D0);
 		}
 	}

@@ -1002,7 +1019,12 @@ static void ata_acpi_unregister_power_resource(struct ata_device *dev)
 
 void ata_acpi_bind(struct ata_device *dev)
 {
+	/* ODD can't be put to D3 cold state, unless it is zero power capable */
+	s32 value = dev->class == ATA_DEV_ATAPI ? PM_QOS_FLAG_NO_POWER_OFF : 0;
+
 	ata_acpi_register_power_resource(dev);
+	dev_pm_qos_add_request(&dev->sdev->sdev_gendev, &dev->pm_qos_req,
+			       DEV_PM_QOS_FLAGS, value);
 }
 
 void ata_acpi_unbind(struct ata_device *dev)

index b928892..9426423 100644
@@ -3856,6 +3856,8 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 				rc = atapi_eh_clear_ua(dev);
 				if (rc)
 					goto rest_fail;
+				if (zpodd_dev_enabled(dev))
+					zpodd_post_resume(dev);
 			}
 		}
 

74 lines not on this page · raw message

index f9235dc..07aaffb 100644
@@ -242,11 +242,19 @@ static inline bool zpodd_dev_enabled(struct ata_device *dev)
 	return dev->zpodd ? true : false;
 }
 void zpodd_on_suspend(struct ata_device *dev);
+bool zpodd_poweroff_ready(struct ata_device *dev);
+void zpodd_post_poweroff(struct ata_device *dev);
+void zpodd_pre_poweron(struct ata_device *dev);
+void zpodd_post_resume(struct ata_device *dev);
 #else /* CONFIG_SATA_ZPODD */
 static inline void zpodd_init(struct ata_device *dev) {}
 static inline void zpodd_exit(struct ata_device *dev) {}
 static inline bool zpodd_dev_enabled(struct ata_device *dev) { return false; }
 static inline void zpodd_on_suspend(struct ata_device *dev) {}
+static inline bool zpodd_poweroff_ready(struct ata_device *dev) { return false; }
+static inline void zpodd_post_poweroff(struct ata_device *dev) {}
+static inline void zpodd_pre_poweron(struct ata_device *dev) {}
+static inline void zpodd_post_resume(struct ata_device *dev) {}
 #endif /* CONFIG_SATA_ZPODD */
 
 #endif /* __LIBATA_H__ */

index d550423..7969e14 100644
@@ -38,6 +38,7 @@
 #include <linux/acpi.h>
 #include <linux/cdrom.h>
 #include <linux/sched.h>
+#include <linux/pm_qos.h>
 
 /*
  * Define if arch has non-standard setup.  This is a _PCI_ standard

@@ -618,6 +619,7 @@ struct ata_device {
 #ifdef CONFIG_ATA_ACPI
 	union acpi_object	*gtf_cache;
 	unsigned int		gtf_filter;
+	struct dev_pm_qos_request pm_qos_req;
 #endif
 #ifdef CONFIG_SATA_ZPODD
 	void			*zpodd;

index 3a82177..27a84de 100644
@@ -1025,6 +1025,8 @@ void ata_acpi_bind(struct ata_device *dev)
 	ata_acpi_register_power_resource(dev);
 	dev_pm_qos_add_request(&dev->sdev->sdev_gendev, &dev->pm_qos_req,
 			       DEV_PM_QOS_FLAGS, value);
+	if (dev->class == ATA_DEV_ATA || zpodd_dev_enabled(dev))
+		dev_pm_qos_expose_flags(&dev->sdev->sdev_gendev, 0);
 }
 
 void ata_acpi_unbind(struct ata_device *dev)

index 6cace66..b0092bb 100644
@@ -18,6 +18,7 @@
 #include <linux/mutex.h>
 #include <linux/idr.h>
 #include <linux/log2.h>
+#include <linux/pm_qos.h>
 
 #include "blk.h"
 

@@ -1595,9 +1596,14 @@ static void disk_events_workfn(struct work_struct *work)
 	unsigned int events;
 	unsigned long intv;
 	int nr_events = 0, i;
+	enum pm_qos_flags_status stat;
 
 	/* check events */
-	events = disk->fops->check_events(disk, clearing);
+	stat = dev_pm_qos_flags(disk->driverfs_dev, PM_QOS_FLAG_NO_POLL);
+	if (stat == PM_QOS_FLAGS_ALL)
+		events = 0;
+	else
+		events = disk->fops->check_events(disk, clearing);
 
 	/* accumulate pending events and schedule next poll if necessary */
 	spin_lock_irq(&ev->lock);

index 5a95013..318a422 100644
@@ -36,6 +36,7 @@ enum pm_qos_flags_status {
 
 #define PM_QOS_FLAG_NO_POWER_OFF	(1 << 0)
 #define PM_QOS_FLAG_REMOTE_WAKEUP	(1 << 1)
+#define PM_QOS_FLAG_NO_POLL		(1 << 3)
 
 struct pm_qos_request {
 	struct plist_node node;

index 27a84de..61a90de 100644
@@ -840,7 +840,8 @@ static int ata_acpi_choose_state(struct ata_device *dev)
 
 	if (zpodd_dev_enabled(dev)) {
 		if (zpodd_poweroff_ready(dev))
-			dev_pm_qos_update_request(&dev->pm_qos_req, 0);
+			dev_pm_qos_update_request(&dev->pm_qos_req,
+						  PM_QOS_FLAG_NO_POLL);
 		else
 			dev_pm_qos_update_request(&dev->pm_qos_req,
 						  PM_QOS_FLAG_NO_POWER_OFF);

index d4dbe42..a37833f 100644
@@ -2,6 +2,7 @@
 #include <linux/cdrom.h>
 #include <linux/pm_runtime.h>
 #include <scsi/scsi_device.h>
+#include <linux/pm_qos.h>
 
 #include "libata.h"
 

@@ -215,6 +216,8 @@ void zpodd_post_resume(struct ata_device *dev)
 
 	zpodd->last_ready = 0;
 	zpodd->zp_ready = false;
+
+	dev_pm_qos_update_request(&dev->pm_qos_req, 0);
 }
 
 static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)

index 97987e7..9cdfb04 100644
@@ -5406,8 +5406,27 @@ static int ata_port_resume(struct device *dev)
 	return rc;
 }
 
+/*
+ * For ODDs, the upper layer will poll for media change every a few seconds,
+ * which will make it enter and leave suspend state every a few seconds. And
+ * as each suspend will cause a hard/soft reset, the gain of runtime suspend
+ * is very little and the ODD may mis-function after constantly being reset.
+ * So the idle callback here will not proceed to suspend if a non-ZPODD capable
+ * ODD is attached to the port.
+ */
 static int ata_port_runtime_idle(struct device *dev)
 {
+	struct ata_port *ap = to_ata_port(dev);
+	struct ata_link *link;
+	struct ata_device *adev;
+
+	ata_for_each_link(link, ap, HOST_FIRST) {
+		ata_for_each_dev(adev, link, ENABLED)
+			if (adev->class == ATA_DEV_ATAPI &&
+			    !zpodd_dev_enabled(adev))
+				return -EBUSY;
+	}
+
 	return pm_runtime_suspend(dev);
 }