Path: tut!draken!kth!sunic!mcvax!uunet!cs.utexas.edu!usc!ucsd!nosc!cod!hall
From: hall@cod.NOSC.MIL (Robert R. Hall)
Newsgroups: comp.os.minix
Subject: patch for kernel/printer.c
Keywords: printer driver
Message-ID: <1614@cod.NOSC.MIL>
Date: 20 Aug 89 03:35:24 GMT
Organization: Naval Ocean Systems Center, San Diego
Lines: 110


With  printer driver version 1.3 and the protected mode version, after
printing 2 pages of a 3 page file the error message 'Printer error'
would apprear on the screen and the print job would terminate.
The following patch is what I found neccessary to correct this problem.
The cdiff is relative to Bruce Evan's protected mode version but patch
will also apply it to version 1.3d with offset warning messages thought.

Robert R. Hall
hall@nosc.mil
--------------------- kernel/printer.c.cdif ----------------------
echo x - printer.c.cdif
sed '/^X/s///' > printer.c.cdif << '/'
X*** /usr/m286pm/kernel/printer.c	Tue Jul 18 21:13:42 1989
X--- printer.c	Sat Aug 19 19:33:55 1989
X***************
X*** 32,44 ****
X  
X  #define NORMAL_STATUS   0x90	/* printer gives this status when idle */
X  #define BUSY_STATUS     0x10	/* printer gives this status when busy */
X  #define ASSERT_STROBE   0x1D	/* strobe a character to the interface */
X  #define NEGATE_STROBE   0x1C	/* enable interrupt on interface */
X  #define SELECT          0x0C	/* select printer bit */
X  #define INIT_PRINTER    0x08	/* init printer bits */
X  #define NO_PAPER        0x20	/* status bit saying that paper is up */
X  #define OFF_LINE        0x10	/* status bit saying that printer not online*/
X- #define PR_ERROR        0x08	/* something is wrong with the printer */
X  #define PR_COLOR_BASE  0x378	/* printer port when color display used */
X  #define PR_MONO_BASE   0x3BC	/* printer port when mono display used */
X  #define CANCELED        -999	/* indicates that command has been killed */
X--- 32,44 ----
X  
X  #define NORMAL_STATUS   0x90	/* printer gives this status when idle */
X  #define BUSY_STATUS     0x10	/* printer gives this status when busy */
X+ #define READY_BIT       0x80    /* printer ready status bit */
X  #define ASSERT_STROBE   0x1D	/* strobe a character to the interface */
X  #define NEGATE_STROBE   0x1C	/* enable interrupt on interface */
X  #define SELECT          0x0C	/* select printer bit */
X  #define INIT_PRINTER    0x08	/* init printer bits */
X  #define NO_PAPER        0x20	/* status bit saying that paper is up */
X  #define OFF_LINE        0x10	/* status bit saying that printer not online*/
X  #define PR_COLOR_BASE  0x378	/* printer port when color display used */
X  #define PR_MONO_BASE   0x3BC	/* printer port when mono display used */
X  #define CANCELED        -999	/* indicates that command has been killed */
X***************
X*** 208,215 ****
X  /* The printer is not ready.  Display a message on the console telling why. */
X  
X    if (status & NO_PAPER) printf("Printer is out of paper\n");
X!   if ((status & OFF_LINE) == 0) printf("Printer is not on line\n");
X!   if ((status & PR_ERROR) == 0) printf("Printer error\n");
X  }
X  
X  
X--- 208,215 ----
X  /* The printer is not ready.  Display a message on the console telling why. */
X  
X    if (status & NO_PAPER) printf("Printer is out of paper\n");
X!   else if ((status & OFF_LINE) == 0) printf("Printer is not on line\n");
X!   else printf("Printer status error is: 0x%x\n", status);
X  }
X  
X  
X***************
X*** 246,254 ****
X  
X    if (pr_busy == FALSE) return;	/* spurious 8259A interrupt */
X  
X!   while (pcount > 0) {
X!   	port_in(port_base + 1, &value);	/* get printer status */
X!   	if ((value&STATUS_MASK) == NORMAL_STATUS) {
X  		/* Everything is all right.  Output another character. */
X  		ch = get_phys_byte(offset);	/* fetch char from user buf */
X  		port_out(port_base, ch);	/* output character */
X--- 246,258 ----
X  
X    if (pr_busy == FALSE) return;	/* spurious 8259A interrupt */
X  
X!   if (pcount > 0) {
X!   	for (i = 0; i < DELAY_COUNT; i++) {
X!   	   port_in(port_base + 1, &value);	/* get printer status */
X!   	   if ((value&READY_BIT) == READY_BIT) break;
X!   	}
X!   	if ((value&STATUS_MASK) == BUSY_STATUS) return;	/* false alarm? */
X!   	else if ((value&STATUS_MASK) == NORMAL_STATUS) {
X  		/* Everything is all right.  Output another character. */
X  		ch = get_phys_byte(offset);	/* fetch char from user buf */
X  		port_out(port_base, ch);	/* output character */
X***************
X*** 257,267 ****
X  		offset++;
X  		pcount--;
X  		cum_count++;	/* count characters output */
X! 		for (i = 0; i < DELAY_COUNT; i++) ;	/* delay loop */
X! 	} else if ((value&STATUS_MASK) == BUSY_STATUS) {
X! 		 	return;		/* printer is busy; wait for interrupt*/
X! 	} else {
X! 		 	break;		/* err: send message to printer task */
X  	}
X    }
X    
X--- 261,267 ----
X  		offset++;
X  		pcount--;
X  		cum_count++;	/* count characters output */
X! 		return;         /* wait for next interrupt */
X  	}
X    }
X    
/