On Thu, Nov 12, 2015 at 1:47 PM, Yong Wu <[email protected]> wrote: > On Wed, 2015-11-11 at 14:54 +0000, Robin Murphy wrote: >> Whilst blindly assuming the worst case for segment boundaries and >> aligning every segment individually is safe from the point of view >> of respecting the device's parameters, it is also undeniably a waste >> of IOVA space. Futhermore, the knock-on effects of more pages than
"Furthermore" (checkpatch actually caught this, not me ;-) ) >> necessary being exposed to device access, additional overhead in page >> table updates and TLB invalidations, etc., are even more undesirable. >> >> Improve matters by taking the actual boundary mask into account to >> actively detect the cases in which we really do need to adjust a >> segment, and avoid wasting space in the remainder. >> >> Signed-off-by: Robin Murphy <[email protected]> >> --- >> >> Hi all, >> >> I've given this some brief testing on Juno with USB and (via magic >> PCI hacks) SATA to confirm that all the +1s and -1s at least seem to >> be in the right places, so I'm throwing it out now for a head-start on >> checking whether it also helps the media folks with the v4l portability >> issues they're up against (I'm confident it should). If all goes well I >> figure I'll repost next week based on rc1 instead of some random local >> development commit. >> >> Robin. > > It works well on MT8173. containing > VDA/VEA(VideoDecodeAccelerator/VideoEncodeAccelerator) unit test. > > Tested-by: Yong Wu <[email protected]> Reviewed-by: Daniel Kurtz <[email protected]> _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
