Re: [PATCH] hvc_console: returning 0 from put_chars is not an error

From: Christian Borntraeger
Date: Thu Oct 15 2009 - 15:27:51 EST


Am Donnerstag 15 Oktober 2009 20:57:45 schrieb Scott Wood:
> Doing it in the backend requires the backend to know whether it's being
> called for printk or for user I/O. In the latter case, we don't want to
> spin, but rather wait for an IRQ (or poll with a timer if there's no IRQ).

Right. Now you have me convinced that we really should have some logic in
hvc_console because, its the only place that knows if it came from printk or
user.

About the backends, there are some that spin until the text is delivered (e.g.
virtio) , others can drop (e.g. iucv is a connection oriented protocol and it
will (and has to) drop if there is no connection).
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