>And here the patch that implement the ioctl (against pre-2.1.127-6):
Woops, excuse me, the volatile flags was neeed... here the correct patch
again against pre-2.1.127-6:
Index: linux/drivers/char/lp.c
diff -u linux/drivers/char/lp.c:1.1.1.4 linux/drivers/char/lp.c:1.1.1.1.12.7
--- linux/drivers/char/lp.c:1.1.1.4 Wed Nov 4 13:06:06 1998
+++ linux/drivers/char/lp.c Thu Nov 5 14:52:13 1998
@@ -21,7 +21,8 @@
* Full efficient handling of printer with buggy irq handshake (now I have
* understood the meaning of the strange handshake). This is done sending new
* characters if the interrupt is just happened, even if the printer say to
- * be still BUSY. This is needed at least with Epson Stylus Color.
+ * be still BUSY. This is needed at least with Epson Stylus Color but
+ * to be safe you must enable this _needed_ feature via ioctl.
* I also fixed the irq on the rising edge of the strobe problem.
* Andrea Arcangeli, 15 Oct 1998
*/
@@ -225,25 +226,36 @@
lp_yield(minor);
status = r_str(minor);
- /*
- * On Epson Stylus Color we must continue even if LP_READY()
- * is false to be efficient. This way is backwards
- * compatible with old not-buggy printers. -arca
- */
- if (LP_NO_ERROR(status) &&
- ((lp_table[minor].irq_detected && LP_NO_ACKING(status)) ||
- LP_READY(status)))
- break;
- /*
- * To have a chance to sleep on the interrupt we should break
- * the polling loop ASAP. Unfortunately there seems to be
- * some hardware that underperform so we leave this
- * configurable at runtime. So when printing with irqs
- * `tunelp /dev/lp0 -c 1' is a must to take the full
- * advantage of the irq. -arca
- */
- if (++count == LP_CHAR(minor))
- return 0;
+ if (lp_table[minor].trustirq)
+ {
+ /*
+ * On Epson Stylus Color we must continue even if
+ * LP_READY() is false to be efficient. This way
+ * _should_ be backwards compatible with old
+ * not-buggy printers but it isn' t. -arca
+ */
+ if (LP_NO_ERROR(status) &&
+ ((lp_table[minor].irq_detected &&
+ LP_NO_ACKING(status)) ||
+ LP_READY(status)))
+ break;
+ if (!LP_POLLED(minor) || ++count == LP_CHAR(minor))
+ return 0;
+ } else {
+ if (LP_NO_ERROR(status) && LP_READY(status))
+ break;
+ /*
+ * To have a chance to sleep on the interrupt we
+ * should break the polling loop ASAP. Unfortunately
+ * there seems to be some hardware that underperform
+ * so we leave this configurable at runtime. So when
+ * printing with irqs `tunelp /dev/lp0 -c 1' should
+ * be a must to take the full advantage of the
+ * irq. -arca
+ */
+ if (++count == LP_CHAR(minor))
+ return 0;
+ }
}
w_dtr(minor, lpchar);
@@ -731,12 +743,17 @@
if (copy_to_user((int *) arg, &status, sizeof(int)))
return -EFAULT;
break;
+ case LPTRUSTIRQ:
+ if (arg)
+ lp_table[minor].trustirq = 1;
+ else
+ lp_table[minor].trustirq = 0;
+ break;
default:
retval = -EINVAL;
}
return retval;
}
-
static struct file_operations lp_fops = {
lp_lseek,
Index: linux/include/linux/lp.h
diff -u linux/include/linux/lp.h:1.1.1.4 linux/include/linux/lp.h:1.1.1.1.12.4
--- linux/include/linux/lp.h:1.1.1.4 Wed Nov 4 13:09:24 1998
+++ linux/include/linux/lp.h Thu Nov 5 15:32:39 1998
@@ -67,7 +67,7 @@
or 0 for polling (no IRQ) */
#define LPGETIRQ 0x0606 /* get the current IRQ number */
#define LPWAIT 0x0608 /* corresponds to LP_INIT_WAIT */
-#ifdef LP_NEED_CAREFUL
+#if 0
#define LPCAREFUL 0x0609 /* call with TRUE arg to require out-of-paper, off-
line, and error indicators good on all writes,
FALSE to ignore them. Default is ignore. */
@@ -80,6 +80,9 @@
#define LPGETSTATS 0x060d /* get statistics (struct lp_stats) */
#endif
#define LPGETFLAGS 0x060e /* get status flags */
+#define LPTRUSTIRQ 0x060f /* cause lp to trust or not the irq, this is needed
+ * to give a sense to the irq printing at least
+ * for Epson Stylus Color */
/* timeout for printk'ing a timeout, in jiffies (100ths of a second).
This is also used for re-checking error conditions if LP_ABORT is
@@ -129,6 +132,7 @@
volatile unsigned int irq_detected:1;
volatile unsigned int irq_missed:1;
unsigned int polled:1;
+ unsigned int trustirq:1;
};
/*
Andrea Arcangeli
-
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