Wait for channel commands to complete after issuing the commands.

The optimisation of only waiting before issuing new commands is
obviously invalid in general and it caused many errors in NIST-PCTS.
I think the errors were mostly for characters sent with the wrong
parity, etc., after a half complete tcsetattr().

Use microtime() instead of a magic loop count to limit the wait.
The wait is a busy-wait :-( and normally takes about 500 usec.

1 files changed, 29 insertions, 15 deletions

diff --git a/sys/i386/isa/cy.c b/sys/i386/isa/cy.c
index b23cf66..118b4ae 100644
--- a/sys/i386/isa/cy.c
+++ b/sys/i386/isa/cy.c
@@ -27,7 +27,7 @@
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: cy.c,v 1.79 1998/12/17 18:43:08 bde Exp $
+ *	$Id: cy.c,v 1.80 1998/12/17 19:23:09 bde Exp $
  */
 
 #include "opt_compat.h"
@@ -355,6 +355,7 @@ ointhand2_t	siointr;
 static	int	cy_units	__P((cy_addr cy_iobase, int cy_align));
 static	int	sioattach	__P((struct isa_device *dev));
 static	void	cd1400_channel_cmd __P((struct com_s *com, int cmd));
+static	void	cd1400_channel_cmd_wait __P((struct com_s *com));
 static	void	cd_etc		__P((struct com_s *com, int etc));
 static	int	cd_getreg	__P((struct com_s *com, int reg));
 static	void	cd_setreg	__P((struct com_s *com, int reg, int val));
@@ -2682,22 +2683,35 @@ cd1400_channel_cmd(com, cmd)
 	struct com_s	*com;
 	int		cmd;
 {
-	/* XXX hsu@clinet.fi: This is always more dependent on ISA bus speed,
-	   as the card is probed every round?  Replaced delaycount with 8k.
-	   Either delaycount has to be implemented in FreeBSD or more sensible
-	   way of doing these should be implemented.  DELAY isn't enough here.
-	   */
-	u_int	maxwait = 5 * 8 * 1024;	/* approx. 5 ms */
-
-	/* wait for processing of previous command to complete */
-	while (cd_getreg(com, CD1400_CCR) && maxwait--)
-		;
+	cd1400_channel_cmd_wait(com);
+	cd_setreg(com, CD1400_CCR, cmd);
+	cd1400_channel_cmd_wait(com);
+}
 
-	if (!maxwait)
-		log(LOG_ERR, "cy: channel command timeout (%d loops) - arrgh\n",
-		    5 * 8 * 1024);
+static void
+cd1400_channel_cmd_wait(com)
+	struct com_s	*com;
+{
+	struct timeval	start;
+	struct timeval	tv;
+	long		usec;
 
-	cd_setreg(com, CD1400_CCR, cmd);
+	if (cd_getreg(com, CD1400_CCR) == 0)
+		return;
+	microtime(&start);
+	for (;;) {
+		if (cd_getreg(com, CD1400_CCR) == 0)
+			return;
+		microtime(&tv);
+		usec = 1000000 * (tv.tv_sec - start.tv_sec) +
+		    tv.tv_usec - start.tv_usec;
+		if (usec >= 5000) {
+			log(LOG_ERR,
+			    "cy%d: channel command timeout (%ld usec)\n",
+			    com->unit, usec);
+			return;
+		}
+	}
 }
 
 static void