lkml.org 
[lkml]   [2012]   [Feb]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] tty: the briq panel isn't a tty, make it use its own locking
Date
From: Alan Cox <alan@linux.intel.com>

The driver appears to be terminall broken, if nobody is maintaining it then
perhaps it should go into staging and the out-tray.

(Fixed bug noted by Jiri)

Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/char/briq_panel.c | 26 +++++++-------------------
1 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/char/briq_panel.c b/drivers/char/briq_panel.c
index 095ab90..3335d07 100644
--- a/drivers/char/briq_panel.c
+++ b/drivers/char/briq_panel.c
@@ -20,6 +20,7 @@
#include <linux/mm.h>
#include <linux/init.h>

+#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/prom.h>
@@ -30,7 +31,7 @@
#define BRIQ_PANEL_VER "1.1 (04/20/2002)"
#define BRIQ_PANEL_MSG0 "Loading Linux"

-static int vfd_is_open;
+static unsigned long vfd_is_open;
static unsigned char vfd[40];
static int vfd_cursor;
static unsigned char ledpb, led;
@@ -66,37 +67,27 @@ static void set_led(char state)

static int briq_panel_open(struct inode *ino, struct file *filep)
{
- tty_lock();
- /* enforce single access, vfd_is_open is protected by BKL */
- if (vfd_is_open) {
- tty_unlock();
+ /* enforce single open */
+ if (test_and_set_bit(0, &vfd_is_open))
return -EBUSY;
}
- vfd_is_open = 1;
-
- tty_unlock();
return 0;
}

static int briq_panel_release(struct inode *ino, struct file *filep)
{
- if (!vfd_is_open)
- return -ENODEV;
-
- vfd_is_open = 0;
-
+ clear_bit(0, &vfd_is_open);
return 0;
}

+/* Note that single open doesn't mean single threaded read or write so all
+ this code is unsafe */
static ssize_t briq_panel_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
unsigned short c;
unsigned char cp;

- if (!vfd_is_open)
- return -ENODEV;
-
c = (inb(BRIQ_PANEL_LED_IOPORT) & 0x000c) | (ledpb & 0x0003);
set_led(' ');
/* upper button released */
@@ -137,9 +128,6 @@ static ssize_t briq_panel_write(struct file *file, const char __user *buf, size_
size_t indx = len;
int i, esc = 0;

- if (!vfd_is_open)
- return -EBUSY;
-
for (;;) {
char c;
if (!indx)


\
 
 \ /
  Last update: 2012-02-23 14:27    [from the cache]
©2003-2011 Jasper Spaans