Serial driver problem from 2.6.12 kernel

Mark A. Greer mgreer at
Sat Sep 10 07:32:20 EST 2005

On Fri, Sep 09, 2005 at 08:17:14AM -0700, goog long wrote:
> Hi all,
> I backported MPSC driver from 2.6.12 to my kernel
> 2.6.10. However, the driver can send characters, but
> cannot receive any characters. Have anyone seen this
> before?
> Please also send your feedback to cecolong at

Hmm, a little sparse on info here so its hard to guess.

The mpsc driver is very much influenced by the platform_data that you
pass to it (since there are so many options).  One possibility
is that you have the max_idle platform_data field set to 0 which means
that the mpsc reciever will not timeout and therefore the mpsc will not
pass to the driver whatever you've typed until your receive buffer fills up
(which you may not have done in your testing).  Try a max_idle value of 40
which seems to work fine for me.  Another possibility, of course, is that
you passed in the wrong irq in the platform_data and therefore are not
getting recieving interrupts.


More information about the Linuxppc-dev mailing list