aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAzael Avalos <coproscefalo@gmail.com>2014-08-04 09:21:01 -0600
committerMatthew Garrett <matthew.garrett@nebula.com>2014-08-16 01:23:54 -0700
commitf6aac652290b31f120fc07c61331e9e0d4b4afb9 (patch)
tree32b430149d6da304e69ec9b1094f0e5f7ed4e783
parentb58b9ffc95511fafcd12c6c7a45ec04e6dcf7d57 (diff)
downloadlinux-f6aac652290b31f120fc07c61331e9e0d4b4afb9.tar.gz
toshiba_acpi: Add extra check to backlight code
Some Toshiba models (most notably Qosmios) come with an incomplete backlight method where the AML code doesn't check for write or read commands and always returns HCI_SUCCESS and the actual brightness (and in some cases the max brightness), thus allowing the backlight interface to be registered without write support. This patch changes the set_lcd_brightness function, checking the returned values for values greater than zero to avoid registering a broken backlight interface. Signed-off-by: Azael Avalos <coproscefalo@gmail.com> Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
-rw-r--r--drivers/platform/x86/toshiba_acpi.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index dfd2243451ba..fa65cec42971 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -872,7 +872,9 @@ static int lcd_proc_open(struct inode *inode, struct file *file)
static int set_lcd_brightness(struct toshiba_acpi_dev *dev, int value)
{
- u32 hci_result;
+ u32 in[HCI_WORDS] = { HCI_SET, HCI_LCD_BRIGHTNESS, 0, 0, 0, 0 };
+ u32 out[HCI_WORDS];
+ acpi_status status;
if (dev->tr_backlight_supported) {
bool enable = !value;
@@ -883,9 +885,20 @@ static int set_lcd_brightness(struct toshiba_acpi_dev *dev, int value)
value--;
}
- value = value << HCI_LCD_BRIGHTNESS_SHIFT;
- hci_write1(dev, HCI_LCD_BRIGHTNESS, value, &hci_result);
- return hci_result == HCI_SUCCESS ? 0 : -EIO;
+ in[2] = value << HCI_LCD_BRIGHTNESS_SHIFT;
+ status = hci_raw(dev, in, out);
+ if (ACPI_FAILURE(status) || out[0] == HCI_FAILURE) {
+ pr_err("ACPI call to set brightness failed");
+ return -EIO;
+ }
+ /* Extra check for "incomplete" backlight method, where the AML code
+ * doesn't check for HCI_SET or HCI_GET and returns HCI_SUCCESS,
+ * the actual brightness, and in some cases the max brightness.
+ */
+ if (out[2] > 0 || out[3] == 0xE000)
+ return -ENODEV;
+
+ return out[0] == HCI_SUCCESS ? 0 : -EIO;
}
static int set_lcd_status(struct backlight_device *bd)