Commit f5efed63 authored Jun 25, 2015 by Mitchel Humpherys

iommu/arm-smmu: Poll TLBSTATUS with a tight loop



Currently we're using a 10us delay while polling the TLB status register
after doing a TLB operation.  These operations almost always finish on
the first iteration or two, so the delay is unnecessary.  Just do a
tight poll.

Change-Id: I7d5787ea92e227ded5a0578c1c647e8317c8ceca
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

parent 2045ecdb

drivers/iommu/arm-smmu.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -815,7 +815,7 @@ static void arm_smmu_tlb_sync_cb(struct arm_smmu_device *smmu,
		writel_relaxed(0, base + ARM_SMMU_CB_TLBSYNC);
		if (readl_poll_timeout_atomic(base + ARM_SMMU_CB_TLBSTATUS, val,
		!(val & TLBSTATUS_SACTIVE),
		10, TLB_LOOP_TIMEOUT))
		0, TLB_LOOP_TIMEOUT))
		dev_err(smmu->dev, "TLBSYNC timeout!\n");
		}