x86/efi-bgrt: Switch pr_err() to pr_debug() for invalid BGRT
authorMatt Fleming <matt.fleming@intel.com>
Fri, 7 Aug 2015 08:36:55 +0000 (09:36 +0100)
committerIngo Molnar <mingo@kernel.org>
Sat, 8 Aug 2015 08:37:39 +0000 (10:37 +0200)
commit248fbcd5aee00f6519a12c5ed3bc3dc0f5e84de5
treec3e5446c700b6224fe7ff96d7dde96b9297dcd8f
parent87db73aebf55554fefaa3eade0a28f282a1511b8
x86/efi-bgrt: Switch pr_err() to pr_debug() for invalid BGRT

It's totally legitimate, per the ACPI spec, for the firmware to
set the BGRT 'status' field to zero to indicate that the BGRT
image isn't being displayed, and we shouldn't be printing an
error message in that case because it's just noise for users. So
swap pr_err() for pr_debug().

However, Josh points that out it still makes sense to test the
validity of the upper 7 bits of the 'status' field, since
they're marked as "reserved" in the spec and must be zero. If
firmware violates this it really *is* an error.

Reported-by: Tom Yan <tom.ty89@gmail.com>
Tested-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438936621-5215-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/platform/efi/efi-bgrt.c