Here's a patch that adds an ioctl to lp for controlling the timeout on
parport_write. Tuning this might give a performance boost to people using
FIFO/DMA transfers.
Tim.
*/
Index: linux/drivers/char/lp.c
diff -u linux/drivers/char/lp.c:1.1.1.4 linux/drivers/char/lp.c:1.5
--- linux/drivers/char/lp.c:1.1.1.4 Thu Jan 6 11:44:23 2000
+++ linux/drivers/char/lp.c Fri Jan 28 17:24:46 2000
@@ -321,6 +321,7 @@
ssize_t retv = 0;
ssize_t written;
size_t copy_size = count;
+ long old_to;
#ifdef LP_STATS
if (jiffies-lp_table[minor].lastcall > LP_TIME(minor))
@@ -346,6 +347,9 @@
/* Go to compatibility mode. */
parport_negotiate (port, IEEE1284_MODE_COMPAT);
+ old_to = parport_set_timeout (lp_table[minor].dev,
+ lp_table[minor].timeout);
+
do {
/* Write the data. */
written = parport_write (port, kbuf, copy_size);
@@ -390,6 +394,9 @@
}
} while (count > 0);
+ /* Not really necessary, but polite. */
+ parport_set_timeout (lp_table[minor].dev, old_to);
+
lp_parport_release (minor);
up (&lp_table[minor].port_mutex);
@@ -588,6 +595,11 @@
if (copy_to_user((int *) arg, &status, sizeof(int)))
return -EFAULT;
break;
+
+ case LPSETTIMEOUT:
+ lp_table[minor].timeout = arg;
+ break;
+
default:
retval = -EINVAL;
}
@@ -854,6 +866,7 @@
init_waitqueue_head (&lp_table[i].waitq);
init_waitqueue_head (&lp_table[i].dataq);
init_MUTEX (&lp_table[i].port_mutex);
+ lp_table[i].timeout = 10 * HZ;
}
if (register_chrdev (LP_MAJOR, "lp", &lp_fops)) {
Index: linux/include/linux/lp.h
diff -u linux/include/linux/lp.h:1.1.1.2 linux/include/linux/lp.h:1.2
--- linux/include/linux/lp.h:1.1.1.2 Thu Oct 14 21:43:13 1999
+++ linux/include/linux/lp.h Fri Jan 28 17:25:36 2000
@@ -89,6 +89,7 @@
#define LPGETSTATS 0x060d /* get statistics (struct lp_stats) */
#endif
#define LPGETFLAGS 0x060e /* get status flags */
+#define LPSETTIMEOUT 0x060f /* set parport timeout */
/* 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
@@ -145,6 +146,7 @@
unsigned int last_error;
struct semaphore port_mutex;
wait_queue_head_t dataq;
+ long timeout;
};
/*
-
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