Date: Fri, 22 Nov 2002 20:02:22 -0700 (MST) From: "M. Warner Losh" <imp@bsdimp.com> To: Maksim.Yevmenkin@cw.com Cc: vova@sw.ru, shizukakudo_99@yahoo.com, freebsd-current@FreeBSD.ORG Subject: Re: Bluetooth questions Message-ID: <20021122.200222.41926856.imp@bsdimp.com> In-Reply-To: <45258A4365C6B24A9832BFE224837D552B1264@sjdcex01.int.exodus.net> References: <45258A4365C6B24A9832BFE224837D552B1264@sjdcex01.int.exodus.net>
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In message: <45258A4365C6B24A9832BFE224837D552B1264@sjdcex01.int.exodus.net>
"Maksim Yevmenkin" <Maksim.Yevmenkin@cw.com> writes:
: I see a lot of "silo overflow" errors under moderate load.
: As a result bytes get dropped on the floor. The Bluetooth
: spec defines extremely simple serial protocol (H4). It simply
: cannot tolerate UARTs that drop bytes. If at least one byte
: gets dropped the entire HCI frame is lost. If HCI frame gets
: dropped then "out of sync" condition exist and all bets are
: off. The only way to get back "in sync" is to send Reset to
: the device. After Reset device goes into standby state and
: all operational state is lost.
OK. That makes sense. Part of the problem even with even fast
interrupt handlers is that interrupts are masked for way way too much
code in -current, as compared to -stable. What baud rate are you
running at? I'm running at 56k, which isn't the full datarate for
115200 baud that could be used. Even with a fast interrupt, you'd get
SIO overflows in current, at least according to some reports.
Hmmm, maybe I should get one of these cards, or one a normal sio cards
and run them at 115200 baud.
Warner
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