On Fri, 2015-04-24 at 13:34 +0200, Svatopluk Kraus wrote: > The add_bounce_page() can be called from _bus_dmamap_load_phys(). > Client virtual address is zero (not valid) in that case. So, client > physical address must be used to get an offset when > BUS_DMA_KEEP_PG_OFFSET flag is set. Note that client physical address > is always valid. > > Svatopluk Kraus
The only user of BUS_DMA_KEEP_PG_OFFSET in the system is USB. If the flag didn't exist, we could do bouncing with a whole lot more efficiency, at least in the ARM world. I wonder if it would be possible to just eliminate the flag (and of course, USB's need for it, which I fully admit I don't understand even a little bit). -- Ian _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
