On Tue, Feb 19, 2019 at 2:44 PM Mikulas Patocka <[email protected]> wrote: > On Tue, 19 Feb 2019, Mikulas Patocka wrote: > > > The patches cd0e00c106722eca40b38ebf11cf134c01901086 and > > 92d7223a74235054f2aa7227d207d9c57f84dca0 fix a theoretical issue where the > > code didn't follow the specification. Unfortunatelly, they also reduce > > timing when port write is followed by a port read. > > > > These reduced timing cause hang on boot on the Avanti platform when > > probing serial ports. This patch adds memory barrier after the outb, outw, > > outl functions, so that there is delay between port write and subsequent > > port read - just like before. > > > > Fixes: cd0e00c10672 ("alpha: io: reorder barriers to guarantee writeX() and > > iowriteX() ordering") > > Cc: [email protected] # v4.17+ > > you can also add: > > Tested-by: Mikulas Patocka <[email protected]>
Acked-by: Arnd Bergmann <[email protected]> but I notice you are missing Signed-off-by. We clearly need this patch, but I assumed the alpha maintainers would pick it up, not me. I merged the original changes since they were cross-architecture, but I don't normally take patches for a particular architecture through the asm-generic tree (or the soc tree for that matter). Arnd
