Re: [PATCH v3 2/3] iommu/arm-smmu-v3: Poll for CMD_SYNC outside cmdq lock

2018-07-19 Thread Leizhen (ThunderTown)
On 2017/10/18 22:04, Robin Murphy wrote: > Even without the MSI trick, we can still do a lot better than hogging > the entire queue while it drains. All we actually need to do for the > necessary guarantee of completion is wait for our particular command to > have been consumed, and as long as

[PATCH v3 2/3] iommu/arm-smmu-v3: Poll for CMD_SYNC outside cmdq lock

2017-10-18 Thread Robin Murphy
Even without the MSI trick, we can still do a lot better than hogging the entire queue while it drains. All we actually need to do for the necessary guarantee of completion is wait for our particular command to have been consumed, and as long as we keep track of where it is there is no need to