Commit a4f08141 authored Jun 29, 2017 by Paul E. McKenney

drivers/ata: Replace spin_unlock_wait() with lock/unlock pair



There is no agreed-upon definition of spin_unlock_wait()'s semantics,
and it appears that all callers could do just as well with a lock/unlock
pair.  This commit therefore eliminates the spin_unlock_wait() call and
associated else-clause and hoists the then-clause's lock and unlock out of
the "if" statement.  This should be safe from a performance perspective
because according to Tejun there should be few if any drivers that don't
set their own error handler.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: <linux-ide@vger.kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>

parent e0892e08

drivers/ata/libata-eh.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -645,12 +645,11 @@ void ata_scsi_cmd_error_handler(struct Scsi_Host host, struct ata_port ap,
		* completions are honored. A scmd is determined to have
		* timed out iff its associated qc is active and not failed.
		*/
		spin_lock_irqsave(ap->lock, flags);
		if (ap->ops->error_handler) {
		struct scsi_cmnd scmd, tmp;
		int nr_timedout = 0;

		spin_lock_irqsave(ap->lock, flags);

		/* This must occur under the ap->lock as we don't want
		a polled recovery to race the real interrupt handler

		@@ -700,12 +699,11 @@ void ata_scsi_cmd_error_handler(struct Scsi_Host host, struct ata_port ap,
		if (nr_timedout)
		__ata_port_freeze(ap);

		spin_unlock_irqrestore(ap->lock, flags);

		/* initialize eh_tries */
		ap->eh_tries = ATA_EH_MAX_TRIES;
		} else
		spin_unlock_wait(ap->lock);
		}
		spin_unlock_irqrestore(ap->lock, flags);

		}
		EXPORT_SYMBOL(ata_scsi_cmd_error_handler);

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