On Jan 7, 2008, at 11:27 PM, Paul Gortmaker wrote: > It seems that if a break is rec'd on the serial console (as per SysRQ > or similar) on some 83xx and 85xx processors, then a pulse of IRQs is > generated which makes the use of SysRQ itself about 99% impossible. I > experimented with trying several ACK strategies, but in the end the > thing which worked best was just to wait for the surge of events to > pass > (a fraction of a second). The number of events can be on the order of > 1000 (as reported by /proc/interrupts) > > I really dislike seeing board specific ifdefs within what should be > board independent code, so I'm hoping that once the problem is known, > that a more elegant solution will pop into someone's head. Or at > least > this will hopefully save someone the grief of re-investigating the > source > and start a discussion. > > I've seen this on two different 834x boards and also an 8548 based > board. At this point, it is not clear to me if the problem extends > beyond these CPU/soc to all with UARTs at 4500/4600. > > While less than ideal, the work-around below which simply ignores the > events does allow a person to use SysRQ on such platforms. > > The definition of the RFE bit (Rx FIFO error) can be found in pretty > much any of the MPC CPU PDFs (for those with 4500/4600 16550s). > > Paul.
This should really get posted to [EMAIL PROTECTED] and probably [EMAIL PROTECTED] lists. - k _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
