Hi Keith Thanks for your kindly reminding.
On 01/19/2018 02:05 PM, Keith Busch wrote: >>> The driver may be giving up on the command here, but that doesn't mean >>> the controller has. We can't just end the request like this because that >>> will release the memory the controller still owns. We must wait until >>> after nvme_dev_disable clears bus master because we can't say for sure >>> the controller isn't going to write to that address right after we end >>> the request. >>> >> Yes, but the controller is going to be reseted or shutdown at the moment, >> even if the controller accesses a bad address and goes wrong, everything will >> be ok after reset or shutdown. :) > Hm, I don't follow. DMA access after free is never okay. Yes, this may cause unexpected memory corruption. Thanks Jianchao