Commit 0b0595bf authored by Peter Huewe's avatar Peter Huewe Committed by Greg Kroah-Hartman

Staging: Panel: prevent driver from calling misc_deregister twice on same ressource

This patch prevents the driver from calling misc_deregister twice on the same
ressouce when unloading the driver.
Unloading the driver without this patch results in a Kernel BUG like this:
Panel driver version 0.9.5 registered on parport0 (io=0x378).
BUG: unable to handle kernel paging request at 0000000000100108
IP: [<ffffffff803c02ee>] misc_deregister+0x2d/0x90
PGD 6caff067 PUD 762b7067 PMD 0
Oops: 0002 [#1] PREEMPT SMP
last sysfs file: /sys/devices/platform/w83627hf.656/in8_input
...

This patch fixes this issue, although maybe not in the best way possible :)

linux version v2.6.32-rc1 - linus git tree, Di 29. Sep 01:10:18 CEST 2009
Signed-off-by: default avatarPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 9fcfeab4
...@@ -2071,11 +2071,15 @@ static void panel_detach(struct parport *port) ...@@ -2071,11 +2071,15 @@ static void panel_detach(struct parport *port)
return; return;
} }
if (keypad_enabled && keypad_initialized) if (keypad_enabled && keypad_initialized) {
misc_deregister(&keypad_dev); misc_deregister(&keypad_dev);
keypad_initialized = 0;
}
if (lcd_enabled && lcd_initialized) if (lcd_enabled && lcd_initialized) {
misc_deregister(&lcd_dev); misc_deregister(&lcd_dev);
lcd_initialized = 0;
}
parport_release(pprt); parport_release(pprt);
parport_unregister_device(pprt); parport_unregister_device(pprt);
...@@ -2211,13 +2215,16 @@ static void __exit panel_cleanup_module(void) ...@@ -2211,13 +2215,16 @@ static void __exit panel_cleanup_module(void)
del_timer(&scan_timer); del_timer(&scan_timer);
if (pprt != NULL) { if (pprt != NULL) {
if (keypad_enabled) if (keypad_enabled) {
misc_deregister(&keypad_dev); misc_deregister(&keypad_dev);
keypad_initialized = 0;
}
if (lcd_enabled) { if (lcd_enabled) {
panel_lcd_print("\x0cLCD driver " PANEL_VERSION panel_lcd_print("\x0cLCD driver " PANEL_VERSION
"\nunloaded.\x1b[Lc\x1b[Lb\x1b[L-"); "\nunloaded.\x1b[Lc\x1b[Lb\x1b[L-");
misc_deregister(&lcd_dev); misc_deregister(&lcd_dev);
lcd_initialized = 0;
} }
/* TODO: free all input signals */ /* TODO: free all input signals */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment