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[RFC,17/20] scsi: qla1280: Remove stale comment about mmiowb()

Message ID 20190222185026.10973-18-will.deacon@arm.com
State Superseded
Headers show
Series Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb()) | expand

Commit Message

Will Deacon Feb. 22, 2019, 6:50 p.m. UTC 
All mmiowb() invocations have been removed, so there's no need to keep
banging on about it.

Signed-off-by: Will Deacon <will.deacon@arm.com>

---
 drivers/scsi/qla1280.c | 10 ----------
 1 file changed, 10 deletions(-)

-- 
2.11.0
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Patch

diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index 93acbc5094f0..327eff67a1ee 100644
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -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);