On Sun, Jul 28, 2019 at 02:18:14 -0400, Michael wrote: > On Sat, 27 Jul 2019 21:35:04 +0200 > Joerg Sonnenberger <jo...@bec.de> wrote: > > > On Fri, Jul 26, 2019 at 07:54:15AM -0300, Jared McNeill wrote: > > > On Fri, 26 Jul 2019, Rin Okuyama wrote: > > > > > > > Also, convert loop of byte-wise copy into memset. > > > > > > I am a bit concerned about this change because IIRC there are platforms > > > where memset etc. cannot be used on device memory. > > > > memset can access memory twice or alignment depending on the platform. > > The question is whether we care about that for the frame buffers though. > > One hazard I can think of is if there's endian-twiddling involved. Some > graphics chip / host bridge combinations will only convert accesses up > to 32bit properly, resulting in 64bit accesses having their upper/lower > 32bit parts swapped on delivery. That should only bite with memcpy() > though.
I remember running into something like this with igsfb(4) on krups. -uwe