Julian Calaby wrote:
On Wed, Jan 5, 2011 at 04:50, David Miller <davem@xxxxxxxxxxxxx> wrote:
From: Daniel Hellstrom <daniel@xxxxxxxxxxx>
Date: Tue, 04 Jan 2011 15:42:45 +0100
David Miller wrote:
From: Julian Calaby <jcalaby@xxxxxxxxxxxxxxxxxxxx>
Date: Sat, 04 Dec 2010 14:55:50 +1100
Signed-off-by: Julian Calaby <julian.calaby@xxxxxxxxx>
Applied.
I think this patch breaks the backwards compatability...
Backwards compatability for who? There is one and only one caller
of this function, and it is marked static and not exported to any
other piece of code in the tree.
With this patch we need to have two different versions of the PROM
emulation implementation, it is a bit sad that it will not work for both
versions of the linux kernel 2.6.36 and 2.6.37, that's all.
I'm probably out of line here, I havn't read the PROMv0 specification,
the old linux implementation was perhaps faulty all along and we made
our PROM code looking at it rather than the PROMv0 spec.
My impression was that pv_nbputchar() in PROM has to be implemented as
non-blocking in order to avoid taking the prom_lock too long, in order
to do that in a linux 2.6.36 kernel the PROM has to return -1 from
pv_nbputchar() when the UART is busy and a 1 when pv_nbputchar()
actually sends a character. However with this patch the pv_nbputchar()
must return a 0 when UART is busy, this means that backwards compability
to the PROM emultation software is lost.
The other point is that sparc64's version works like this, so why
should sparc32's version be different?
Good point. Havn't looked at the SPARC64 code. Probably we should have
submitted a patch for the old bad behaviour before.
We can live with two different versions of the PROM... there are more
important things in life :)
Thank you,
Daniel
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
