[v12,1/5] block: add a flag to identify PM request

Message ID 1364010148-8584-2-git-send-email-aaron.lu@intel.com
State Not Applicable
Delegated to: David Miller
Headers show

Commit Message

Aaron Lu March 23, 2013, 3:42 a.m.
From: Lin Ming <ming.m.lin@intel.com>

Add a flag REQ_PM to identify the request is PM related, such requests
will not change the device request queue's runtime status. It is
intended to be used in driver's runtime PM callback, so that driver can
perform some IO to the device there with the queue's runtime status
unaffected. e.g. in SCSI disk's runtime suspend callback, the disk will
be put into stopped power state, and this require sending a command to
the device. Such command processing should not change the disk's runtime

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
 include/linux/blk_types.h | 2 ++
 1 file changed, 2 insertions(+)


diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index cdf1119..fcc1ce2 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -175,6 +175,7 @@  enum rq_flag_bits {
 	__REQ_IO_STAT,		/* account I/O stat */
 	__REQ_MIXED_MERGE,	/* merge of different types, fail separately */
 	__REQ_KERNEL, 		/* direct IO to kernel pages */
+	__REQ_PM,		/* runtime pm request */
 	__REQ_NR_BITS,		/* stops here */
@@ -223,5 +224,6 @@  enum rq_flag_bits {
 #define REQ_SECURE		(1 << __REQ_SECURE)
 #define REQ_KERNEL		(1 << __REQ_KERNEL)
+#define REQ_PM			(1 << __REQ_PM)
 #endif /* __LINUX_BLK_TYPES_H */