At Fri, 14 Feb 2014 14:34:07 +0200,
Mika Westerberg wrote:

quoted

This reverts commit e18ac62fa4b3f16234bab0d5a6627c57dbae9e7e.

The referenced commit added HP EliteBook Revolve 810 to the ACPI video
detected blacklist so that only the native Intel backlight interface was
exported.

However, this turned to be wrong solution after all. The ACPI video
interface works and as long as we only use that there are no problems. So
we can revert this commit and stick to use the backlight interface provided
by the ACPI video driver.

(Using Intel native interface will not work after resume since the ACPI
video driver will restore it's state which takes control over the native
one. That's a separate thing and should be addressed in the ACPI video
driver, I suppose.)

References: https://bugzilla.kernel.org/show_bug.cgi?id=70231
Cc: Aaron Lu <redacted>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
Rafael, 

This turned out to be misunderstanding from my side. I should have
investigated this further before submitting the original patch. Sorry about
that.

Aaron,

Thanks for the investigation and pointing me to the right direction (e.g to
use acpi_video0 over the native one).

Could you check whether the ACPI video still really works even if you
remove the recent acpi_osi blacklist entry below?  It might be that
BIOS changed its mind to behave more kindly as if handling for Win7.


Takashi

---

diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
index 10e4964d051a..64d14406465d 100644
--- a/drivers/acpi/blacklist.c
+++ b/drivers/acpi/blacklist.c

@@ -322,6 +322,7 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
 		     DMI_MATCH(DMI_PRODUCT_VERSION, "2349D15"),
 		},
 	},
+#if 0
 	{
 	.callback = dmi_disable_osi_win8,
 	.ident = "HP ProBook 2013 models",

@@ -372,6 +373,7 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8780w"),
 		},
 	},
+#endif
 
 	/*
 	 * BIOS invocation of _OSI(Linux) is almost always a BIOS bug.