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authorRichard Purdie <rpurdie@rpsys.net>2007-02-09 01:25:09 +0300
committerRichard Purdie <rpurdie@rpsys.net>2007-02-20 11:38:45 +0300
commit28ee086d5b36aab2931f6740e409bb0fb6c65e5f (patch)
tree0a308c80affcc39c2c869f29f1109e5ee9d6140f /drivers/usb
parenta8db3c1948eb30cd6988b5b96b654f591e6280b1 (diff)
downloadlinux-28ee086d5b36aab2931f6740e409bb0fb6c65e5f.tar.xz
backlight: Fix external uses of backlight internal semaphore
backlight_device->sem has a very specific use as documented in the header file. The external users of this are using it for a different reason, to serialise access to the update_status() method. backlight users were supposed to implement their own internal serialisation of update_status() if needed but everyone is doing things differently and incorrectly. Therefore add a global mutex to take care of serialisation for everyone, once and for all. Locking for get_brightness remains optional since most users don't need it. Also update the lcd class in a similar way. Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/misc/appledisplay.c6
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c
index 416cde5893af..cd2c5574cf93 100644
--- a/drivers/usb/misc/appledisplay.c
+++ b/drivers/usb/misc/appledisplay.c
@@ -189,11 +189,9 @@ static void appledisplay_work(struct work_struct *work)
container_of(work, struct appledisplay, work.work);
int retval;
- up(&pdata->bd->sem);
retval = appledisplay_bl_get_brightness(pdata->bd);
if (retval >= 0)
pdata->bd->props->brightness = retval;
- down(&pdata->bd->sem);
/* Poll again in about 125ms if there's still a button pressed */
if (pdata->button_pressed)
@@ -288,9 +286,7 @@ static int appledisplay_probe(struct usb_interface *iface,
}
/* Try to get brightness */
- up(&pdata->bd->sem);
brightness = appledisplay_bl_get_brightness(pdata->bd);
- down(&pdata->bd->sem);
if (brightness < 0) {
retval = brightness;
@@ -299,9 +295,7 @@ static int appledisplay_probe(struct usb_interface *iface,
}
/* Set brightness in backlight device */
- up(&pdata->bd->sem);
pdata->bd->props->brightness = brightness;
- down(&pdata->bd->sem);
/* save our data pointer in the interface device */
usb_set_intfdata(iface, pdata);