path: root/include/scsi
diff options
authorAaron Lu <aaron.lu@intel.com>2013-01-23 15:09:32 +0800
committerJeff Garzik <jgarzik@redhat.com>2013-01-25 15:36:43 -0500
commit6f4c827e68a78731c6c75df69bf7b75b029ec70c (patch)
tree5113f12fc6fd5c7e2769aa19c2a1bb59ea647652 /include/scsi
parent6c7f1e2f12f6f37ddda01180c9e5c407eccce616 (diff)
[libata] scsi: no poll when ODD is powered off
When the ODD is powered off, any action the user did to the ODD that would generate a media event will trigger an ACPI interrupt, so the poll for media event is no longer necessary. And the poll will also cause a runtime status change, which will stop the ODD from staying in powered off state, so the poll should better be stopped. But since we don't have access to the gendisk structure in LLDs, here comes the disk_events_disable_depth for scsi device. This field is a hint set by LLDs to convey information to upper layer drivers. A value of 0 means media poll is necessary for the device, while values above 0 means media poll is not needed and should better be skipped. So we can increase its value when we are to power off the ODD in ATA layer and decrease its value when the ODD is powered on, effectively silence the media events poll. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'include/scsi')
1 files changed, 4 insertions, 0 deletions
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index e65c62e82c5a..bb1371bf171d 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -161,6 +161,8 @@ struct scsi_device {
unsigned wce_default_on:1; /* Cache is ON by default */
unsigned no_dif:1; /* T10 PI (DIF) should be disabled */
+ atomic_t disk_events_disable_depth; /* disable depth for disk events */
DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
struct list_head event_list; /* asserted events */
struct work_struct event_work;
@@ -397,6 +399,8 @@ extern int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
int data_direction, void *buffer, unsigned bufflen,
struct scsi_sense_hdr *, int timeout, int retries,
int *resid);
+extern void sdev_disable_disk_events(struct scsi_device *sdev);
+extern void sdev_enable_disk_events(struct scsi_device *sdev);
extern int scsi_autopm_get_device(struct scsi_device *);