diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/thinkpad_acpi.c | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c index 01bed937d38..f15a58f7403 100644 --- a/drivers/misc/thinkpad_acpi.c +++ b/drivers/misc/thinkpad_acpi.c @@ -3000,12 +3000,16 @@ static struct backlight_ops ibm_backlight_data = { .update_status = brightness_update_status, }; +static struct mutex brightness_mutex; + static int __init brightness_init(struct ibm_init_struct *iibm) { int b; vdbg_printk(TPACPI_DBG_INIT, "initializing brightness subdriver\n"); + mutex_init(&brightness_mutex); + if (!brightness_mode) { if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO) brightness_mode = 2; @@ -3092,27 +3096,44 @@ static int brightness_get(struct backlight_device *bd) static int brightness_set(int value) { - int cmos_cmd, inc, i; - int current_value = brightness_get(NULL); + int cmos_cmd, inc, i, res; + int current_value; if (value > 7) return -EINVAL; + res = mutex_lock_interruptible(&brightness_mutex); + if (res < 0) + return res; + + current_value = brightness_get(NULL); + if (current_value < 0) { + res = current_value; + goto errout; + } + cmos_cmd = value > current_value ? TP_CMOS_BRIGHTNESS_UP : TP_CMOS_BRIGHTNESS_DOWN; inc = value > current_value ? 1 : -1; + res = 0; for (i = current_value; i != value; i += inc) { if ((brightness_mode & 2) && - issue_thinkpad_cmos_command(cmos_cmd)) - return -EIO; + issue_thinkpad_cmos_command(cmos_cmd)) { + res = -EIO; + goto errout; + } if ((brightness_mode & 1) && - !acpi_ec_write(brightness_offset, i + inc)) - return -EIO; + !acpi_ec_write(brightness_offset, i + inc)) { + res = -EIO; + goto errout;; + } } - return 0; +errout: + mutex_unlock(&brightness_mutex); + return res; } static int brightness_read(char *p) |