On Thu, 14 Aug 2003, Poul-Henning Kamp wrote: > In message <[EMAIL PROTECTED]>, Mark Murray wr > ites: > > >Would it be a useful exercise for the minority(?) of users who use this > >driver to either see if it can be effectively newbussed or turned into > >a port or both? > > The main problem is the code which hi-jacks the i8254 and kicks off > up to 20000 interrupts per second.
What problem is this, except that 20000 interrupts per second is too small for current hardware? Hmm, use of the interrupts has been broken in -current by incompletely turning clkintr() into a fast interrupt handler. pcaintr() is not a fast interrupt handler, but clkintr() just calls it if pca is active. pca uses splhigh() for locking, but splhigh is null in -current and doesn't lock out fast interrupts anyway. If pca were locked by Giant, then the large interrupt latency of Giant would show up as large distortion. Bruce _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[EMAIL PROTECTED]"
