Messages in this thread Patch in this message | | | Date | Fri, 28 Jan 2000 17:28:31 +0000 (GMT) | From | Tim Waugh <> | Subject | [patch] 2.3.41pre4: lp ioctl for controlling parport timeout |
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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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