Date: Fri, 6 Apr 2001 06:40:03 -0700 (PDT) From: Bruce Evans <bde@zeta.org.au> To: freebsd-bugs@FreeBSD.org Subject: Re: i386/26261: silo overflow problem in sio driver Message-ID: <200104061340.f36De3J89525@freefall.freebsd.org>
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The following reply was made to PR i386/26261; it has been noted by GNATS. From: Bruce Evans <bde@zeta.org.au> To: WATANABE Kiyoshi <aab10490@pop16.odn.ne.jp> Cc: freebsd-gnats-submit@FreeBSD.org, richw@webcom.com Subject: Re: i386/26261: silo overflow problem in sio driver Date: Fri, 6 Apr 2001 23:32:33 +1000 (EST) On Fri, 6 Apr 2001, WATANABE Kiyoshi wrote: > > Silo overflows are caused by non-sio hardware hogging the bus or by > > interrupt latency outside the driver. They should never occur at low > > I agree. > > > speeds like 115200 bps even on 386/20's (except in -current, where > > interrupt latency outside the driver is certainly broken enough to > > matter even on 486DX2/66's). > > I guess that INTR_TYPE_FAST flag is suspicious. > Only sio, cy, and loran use this flag. It is the main thing that is supposed to make silo overflows not happen. I don't know of any bugs in it. > > but I cant get silo overflows in my Celeron-700Mhz/i810 machine. > so I cant test. You can probably get them by removing the INTR_TYPE_FAST flag :-). Try toggling the caps lock key while input is arriving. For some (most?) keyboards, setting the LEDs takes 2-5 msec. Tty interrupts are disabled while the LEDs are being set, and 2-5 msec is long enough to cause silo overflows. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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