Re: hvc_console change results in corrupt oops output

On Mon, Jul 04, 2011 at 11:56:27PM +1000, Benjamin Herrenschmidt wrote:

On Mon, 2011-07-04 at 20:57 +1000, Anton Blanchard wrote:

 .../...

quoted

The hypervisor gives us a busy return, so we could retry a number of
times instead of dropping it on the floor. We'd need to do it in the
hvc_console driver - the tty drivers share the same backend
functions so we can't hide it in the pseries put_chars function.

For kernel console, I don't see why not wait forever ... If the
underlying backend really lost the connection it can always return a
negative error no ?

Or we could have "well defined" return codes for "wait forever" vs.
"drop this" ... maybe return -EAGAIN.

I will check this again for my hvc_iucv back-end.  Meanwhile a found
an old thread discussing the same issue.  It covers some differences
between console and ttys which actually does not matter for hvc-backend
because of the shared put_chars() routine.

You can read the thread on lkml.org: http://lkml.org/lkml/2009/10/15/149


Kind regards,
  Hendrik