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authorPatrick Rudolph <patrick.rudolph@9elements.com>2020-02-28 10:38:55 +0100
committerPatrick Georgi <pgeorgi@google.com>2020-03-11 14:50:35 +0000
commit6dc488a6781e4b0ecd0d4cb963d40709f17df0ef (patch)
tree69464ae245cbbeaddcb7e7df6246c1c84faded42
parenta02f00e5d6aa8693bfd4a8c66b89c85539555329 (diff)
downloadcoreboot-6dc488a6781e4b0ecd0d4cb963d40709f17df0ef.tar.xz
drivers/intel/gma/acpi: Prevent DivideByZero error
In case backlight control isn't enabled BCLM is zero. Return early instead of running into a DivideByZero error. This happens on devices that don't have backlight control, like desktops and servers. The proper fix is to not include those ACPI methods, but that requires a much bigger refactoring. Change-Id: Ie9bdb00949d6d44fd99321db556d6008d2d12a7f Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/39158 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
-rw-r--r--src/drivers/intel/gma/acpi/configure_brightness_levels.asl5
1 files changed, 5 insertions, 0 deletions
diff --git a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
index 3ec74119f1..21f0b2318e 100644
--- a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
+++ b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
@@ -122,6 +122,11 @@
/* Find value closest to BCLV in BRIG (which must be ordered) */
Method (XBQC, 0, NotSerialized)
{
+ /* Prevent DivideByZero if backlight control isn't enabled */
+ If (BCLM == 0)
+ {
+ Return (Zero)
+ }
/* Local0: current percentage */
Store (DRCL (Multiply (BCLV, 100), BCLM), Local0)