tree 42cd8aaecca37a7fce9d81d20fcd78f9d86647b1
parent 63f21a56f1cc0b800a4c00349c59448f82473d19
author Hendrik Brueckner <brueckner@linux.vnet.ibm.com> 1309902618 +0000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> 1311052385 +1000

hvc_console: Improve tty/console put_chars handling

Currently, the hvc_console_print() function drops console output if the
hvc backend's put_chars() returns 0.  This patch changes this behavior
to allow a retry through returning -EAGAIN.

This change also affects the hvc_push() function.  Both functions are
changed to handle -EAGAIN and to retry the put_chars() operation.

If a hvc backend returns -EAGAIN, the retry handling differs:

  - hvc_console_print() spins to write the complete console output.
  - hvc_push() behaves the same way as for returning 0.

Now hvc backends can indirectly control the way how console output is
handled through the hvc console layer.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>