On Thu, 1 Apr 2010, Darcy L. Watkins wrote: > In arch/powerpc/sysdev/uic.c changing all the spinlock functions for > &uic->lock to their raw_ equivalents appears to fix it. Also since the Yes, that lock needs to be raw. > invoking code appears to already have an rtmutex locked already whenever > any of these paths are executed, I also tried simply commenting out the > whole UIC spinlock altogether and that works too. > > Perhaps someone more familiar with the powerpc kernel code can advise me > as to whether or not the uic->lock spinlock in uic.c is redundant (i.e. > correct to remove it) or the raw spinlock is still needed. Looks redundant, but I need to have a closer look. Converted it to raw for now. > I have also observed the following type of errors in dmesg output... > > [ 145.583931] ttyS0: 1 input overrun(s) > > I observe these whether I have the earlier BUG present or either of my > changes to get rid of the BUG error messages. > > All of these conditions also appear when I build kernel 2.6.31.12-rt21 > for the same hardware. > > They do NOT appear when I build kernel 2.6.29.6-rt24 for the same > hardware. They also do NOT appear for kernel 2.6.30, 2.6.31 or 2.6.33 Hmm. Which UART driver is this ? Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
