Date: Thu, 4 Feb 1999 05:45:14 -0800 (PST) From: Bruce Evans <bde@FreeBSD.ORG> To: cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: cvs commit: src/sys/i386/isa sio.c Message-ID: <199902041345.FAA38267@freefall.freebsd.org>
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bde 1999/02/04 05:45:14 PST
Modified files:
sys/i386/isa sio.c
Log:
Set up interrupt-level input buffering dynamically depending on
the input speed, so that it can work at speeds larger than 115200
bps without being flow controlled. The buffer is twice as large
as before at 115200 bps and half as large as before at low speeds
Use a single interrupt-level buffer instead of ping-pong buffers
because the simplifications provided by ping-pong buffers became
complications.
This change is over-engineered. Statically configured buffering
was simpler and faster, and increasing the buffer size to support
1.5Mbps would cost about 1 US cent's worth of RAM per port, but I
was interested in the buffer switching mechanism.
Revision Changes Path
1.227 +177 -111 src/sys/i386/isa/sio.c
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