Commit 161861a4 authored by Will Deacon's avatar Will Deacon
Browse files

scsi/qla1280: Remove stale comment about mmiowb() 



All mmiowb() invocations have been removed, so there's no need to keep
banging on about it.

Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent fb24ea52

drivers/scsi/qla1280.c

+0 −10
Original line number Diff line number Diff line
@@ -3363,16 +3363,6 @@ qla1280_isp_cmd(struct scsi_qla_host *ha) 


	/*

	 * Update request index to mailbox4 (Request Queue In).

	 * The mmiowb() ensures that this write is ordered with writes by other

	 * CPUs.  Without the mmiowb(), it is possible for the following:

	 *    CPUA posts write of index 5 to mailbox4

	 *    CPUA releases host lock

	 *    CPUB acquires host lock

	 *    CPUB posts write of index 6 to mailbox4

	 *    On PCI bus, order reverses and write of 6 posts, then index 5,

	 *       causing chip to issue full queue of stale commands

	 * The mmiowb() prevents future writes from crossing the barrier.

	 * See Documentation/driver-api/device-io.rst for more information.

	 */

	WRT_REG_WORD(&reg->mailbox4, ha->req_ring_index);