On Sat, Jun 08, 2019 at 02:21:23PM +1000, Benjamin Herrenschmidt wrote: > > > Please try the attached patch. I'm not really pleased with it and I will > > continue to determine why the fallback to a 30-bit mask fails, but at least > > this > > one works for me. > > Your patch only makes sense if the device is indeed capable of > addressing 31-bits. > > So either the driver is buggy and asks for a too small mask in which > case your patch is ok, or it's not and you're just going to cause all > sort of interesting random problems including possible memory > corruption.
Well, my patches changes ZONE_DMA to be 30-bits instead of 31, and thus should allow requesting a 30-bit mask to succeed.
