[kernel/f16] Allow ACPI backlight to still work if _DOS isn't present (rhbz 834910)

[Josh Boyer]

commit 523e29cf0b869ec8248eace6b8a38152696c618e
Author: Josh Boyer <jwboyer at redhat.com>
Date:   Tue Jul 3 10:23:03 2012 -0400

    Allow ACPI backlight to still work if _DOS isn't present (rhbz 834910)

 ...PI-backlight-control-if-_DOS-doesnt-exist.patch |   34 ++++++++++++++++++++
 kernel.spec                                        |   11 ++++++-
 2 files changed, 44 insertions(+), 1 deletions(-)
---
diff --git a/ACPI-video-Still-use-ACPI-backlight-control-if-_DOS-doesnt-exist.patch b/ACPI-video-Still-use-ACPI-backlight-control-if-_DOS-doesnt-exist.patch
new file mode 100644
index 0000000..a897111
--- /dev/null
+++ b/ACPI-video-Still-use-ACPI-backlight-control-if-_DOS-doesnt-exist.patch
@@ -0,0 +1,34 @@
+
+This is a regression introduced by commit
+ea9f8856bd6d4ed45885b06a338f7362cd6c60e5
+https://bugzilla.kernel.org/show_bug.cgi?id=43168
+
+Some platforms don't have _DOS control method, but the ACPI
+backlight still works.
+We should not invoke _DOS for these platforms.
+
+CC : Igor Murzov <intergalactic.anonymous at gmail.com>
+Signed-off-by: Zhang Rui <rui.zhang at intel.com>
+---
+ drivers/acpi/video.c |    2 ++
+ 1 file changed, 2 insertions(+)
+
+Index: rtd3/drivers/acpi/video.c
+===================================================================
+--- rtd3.orig/drivers/acpi/video.c
++++ rtd3/drivers/acpi/video.c
+@@ -558,6 +558,8 @@ acpi_video_bus_DOS(struct acpi_video_bus
+ 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
+ 	struct acpi_object_list args = { 1, &arg0 };
+ 
++	if (!video->cap._DOS)
++		return 0;
+ 
+ 	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
+ 		return -EINVAL;
+
+
+--
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\ No newline at end of file
diff --git a/kernel.spec b/kernel.spec
index c1ffb6f..8c03778 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -54,7 +54,7 @@ Summary: The Linux kernel
 # For non-released -rc kernels, this will be appended after the rcX and
 # gitX tags, so a 3 here would become part of release "0.rcX.gitX.3"
 #
-%global baserelease 3
+%global baserelease 4
 %global fedora_build %{baserelease}
 
 # base_sublevel is the kernel version we're starting with and patching
@@ -791,6 +791,9 @@ Patch22040: mm-correctly-synchronize-rss-counters-at-exit-exec.patch
 #rhbz 832927
 Patch22041: ath9k-fix-panic-caused-by-returning-a-descriptor-we-.patch
 
+#rhbz 834910
+Patch22042: ACPI-video-Still-use-ACPI-backlight-control-if-_DOS-doesnt-exist.patch
+
 # END OF PATCH DEFINITIONS
 
 %endif
@@ -1468,6 +1471,9 @@ ApplyPatch mm-correctly-synchronize-rss-counters-at-exit-exec.patch
 #rhbz 832927
 ApplyPatch ath9k-fix-panic-caused-by-returning-a-descriptor-we-.patch
 
+#rhbz 834910
+ApplyPatch ACPI-video-Still-use-ACPI-backlight-control-if-_DOS-doesnt-exist.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -2206,6 +2212,9 @@ fi
 # and build.
 
 %changelog
+* Tue Jul 3 2012 Josh Boyer <jwboyer at redhat.com>
+- Allow ACPI backlight to still work if _DOS isn't present (rhbz 834910)
+
 * Fri Jun 29 2012 John W. Linville <linville at redhat.com>
 - ath9k: fix panic caused by returning a descriptor we have... (rhbz 832927)