On Wed, 2017-01-18 at 03:12 +0000, Ashizuka, Yuusuke wrote: > indeed. > > In the case of TSO with i.MX6 system (highmem enabled) with 2GB memory, > "this_frag->page.p" did not become highmem area. > (We confirmed by transferring about 100MB of files) > > However, in the case of non-tso on an i.MX6 system with 2GB of memory, > "this_frag->page.p" may become a highmem area. > (Occurred with approximately 2MB of file transfer) > > For non-tso only, I do not know the reason why "this_frag-> page.p" > in this driver shows highmem area.
This worries me, since this driver does not set NETIF_F_HIGHDMA in its features. No packet should be given to this driver with a highmem fragment Check is done in illegal_highdma() in net/core/dev.c
