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Date: Wed, 29 Jan 1997 13:50:07 -0800 (PST)
From: Bruce Evans <bde>
Message-Id: <199701292150.NAA24177@freefall.freebsd.org>
To: CVS-committers, cvs-all, cvs-sys
Subject: cvs commit:  src/sys/i386/isa sio.c
Sender: owner-cvs-sys@FreeBSD.ORG
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bde         97/01/29 13:50:06

  Modified:    sys/i386/isa  sio.c
  Log:
  Fixes and workarounds for Hayes ESP:
  - don't uselessly initialize the fifo "DMA" bit at attach time.
  - initialize the fifo "DMA" bit at open time.  Without this, the device
    interrupts for every character received, reducing input performance
    to that of an 8250.
  - don't uselessly initialize the fifo trigger level to 8 (scaled to
    256) at attach time.
  - don't scale the fifo trigger level to 512 bytes.  The driver's pseudo-
    dma buffer has size 256, so it can't handle bursts of size 512 or 256.
    It should be able to handle the second lowest ftl (2 scaled to 64).
  - don't reset the fifos in siostop().  Reset triggers a hardware bug
    involving wedging of the output interrupt bit  This workaround
    unfortunately requires ESP support to be configured.
  
  Revision  Changes    Path
  1.157     +25 -7     src/sys/i386/isa/sio.c