From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The powermac has a kernel-based driver for controlling the backlight from
the keyboard that used to call into some fbdev's from interrupt contexts.
This patch moves it to a workqueue (and additionally makes sure the console
semaphore is taken and held).
I hope I'll replace this by the new backlight framework in a future kernel
version, but for now, this will fix the immediate issues with radeon.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/ppc/platforms/pmac_backlight.c | 73 +++++++++++++++++++++-------
1 files changed, 55 insertions(+), 18 deletions(-)
diff -puN arch/ppc/platforms/pmac_backlight.c~ppc32-move-powermac-backlight-stuff-to-a-workqueue arch/ppc/platforms/pmac_backlight.c
--- 25/arch/ppc/platforms/pmac_backlight.c~ppc32-move-powermac-backlight-stuff-to-a-workqueue 2005-03-10 22:06:06.000000000 -0800
+++ 25-akpm/arch/ppc/platforms/pmac_backlight.c 2005-03-10 22:06:06.000000000 -0800
@@ -25,14 +25,19 @@
#include <linux/adb.h>
#include <linux/pmu.h>
-static struct backlight_controller *backlighter = NULL;
-static void* backlighter_data = NULL;
-static int backlight_autosave = 0;
+static struct backlight_controller *backlighter;
+static void* backlighter_data;
+static int backlight_autosave;
static int backlight_level = BACKLIGHT_MAX;
static int backlight_enabled = 1;
+static int backlight_req_level = -1;
+static int backlight_req_enable = -1;
-void __pmac
-register_backlight_controller(struct backlight_controller *ctrler, void *data, char *type)
+static void backlight_callback(void *);
+static DECLARE_WORK(backlight_work, backlight_callback, NULL);
+
+void __pmac register_backlight_controller(struct backlight_controller *ctrler,
+ void *data, char *type)
{
struct device_node* bk_node;
char *prop;
@@ -83,16 +88,18 @@ register_backlight_controller(struct bac
backlight_level = req.reply[0] >> 4;
}
#endif
+ acquire_console_sem();
if (!backlighter->set_enable(1, backlight_level, data))
backlight_enabled = 1;
+ release_console_sem();
- printk(KERN_INFO "Registered \"%s\" backlight controller, level: %d/15\n",
- type, backlight_level);
+ printk(KERN_INFO "Registered \"%s\" backlight controller,"
+ "level: %d/15\n", type, backlight_level);
}
EXPORT_SYMBOL(register_backlight_controller);
-void __pmac
-unregister_backlight_controller(struct backlight_controller *ctrler, void *data)
+void __pmac unregister_backlight_controller(struct backlight_controller
+ *ctrler, void *data)
{
/* We keep the current backlight level (for now) */
if (ctrler == backlighter && data == backlighter_data)
@@ -100,22 +107,29 @@ unregister_backlight_controller(struct b
}
EXPORT_SYMBOL(unregister_backlight_controller);
-int __pmac
-set_backlight_enable(int enable)
+static int __pmac __set_backlight_enable(int enable)
{
int rc;
if (!backlighter)
return -ENODEV;
- rc = backlighter->set_enable(enable, backlight_level, backlighter_data);
+ acquire_console_sem();
+ rc = backlighter->set_enable(enable, backlight_level,
+ backlighter_data);
if (!rc)
backlight_enabled = enable;
+ release_console_sem();
return rc;
}
+int __pmac set_backlight_enable(int enable)
+{
+ backlight_req_enable = enable;
+ schedule_work(&backlight_work);
+}
+
EXPORT_SYMBOL(set_backlight_enable);
-int __pmac
-get_backlight_enable(void)
+int __pmac get_backlight_enable(void)
{
if (!backlighter)
return -ENODEV;
@@ -123,8 +137,7 @@ get_backlight_enable(void)
}
EXPORT_SYMBOL(get_backlight_enable);
-int __pmac
-set_backlight_level(int level)
+static int __pmac __set_backlight_level(int level)
{
int rc = 0;
@@ -134,10 +147,12 @@ set_backlight_level(int level)
level = BACKLIGHT_OFF;
if (level > BACKLIGHT_MAX)
level = BACKLIGHT_MAX;
+ acquire_console_sem();
if (backlight_enabled)
rc = backlighter->set_level(level, backlighter_data);
if (!rc)
backlight_level = level;
+ release_console_sem();
if (!rc && !backlight_autosave) {
level <<=1;
if (level & 0x10)
@@ -146,13 +161,35 @@ set_backlight_level(int level)
}
return rc;
}
+int __pmac set_backlight_level(int level)
+{
+ backlight_req_level = level;
+ schedule_work(&backlight_work);
+}
+
EXPORT_SYMBOL(set_backlight_level);
-int __pmac
-get_backlight_level(void)
+int __pmac get_backlight_level(void)
{
if (!backlighter)
return -ENODEV;
return backlight_level;
}
EXPORT_SYMBOL(get_backlight_level);
+
+static void backlight_callback(void *dummy)
+{
+ int level, enable;
+
+ do {
+ level = backlight_req_level;
+ enable = backlight_req_enable;
+ mb();
+
+ if (level >= 0)
+ __set_backlight_level(level);
+ if (enable >= 0)
+ __set_backlight_enable(enable);
+ } while(cmpxchg(&backlight_req_level, level, -1) != level ||
+ cmpxchg(&backlight_req_enable, enable, -1) != enable);
+}
_