From owner-freebsd-bugs Fri Apr 6 6:40: 7 2001 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id F3F5E37B42C for ; Fri, 6 Apr 2001 06:40:03 -0700 (PDT) (envelope-from gnats@FreeBSD.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.11.1/8.11.1) id f36De3J89525; Fri, 6 Apr 2001 06:40:03 -0700 (PDT) (envelope-from gnats) Date: Fri, 6 Apr 2001 06:40:03 -0700 (PDT) Message-Id: <200104061340.f36De3J89525@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: Bruce Evans Subject: Re: i386/26261: silo overflow problem in sio driver Reply-To: Bruce Evans Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org The following reply was made to PR i386/26261; it has been noted by GNATS. From: Bruce Evans To: WATANABE Kiyoshi 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