linux-kernel - Re: [PATCH] x86/efi-bgrt: remove the check of the version field

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Message-ID: <20160811084844.GA4343@gmail.com>
Date:	Thu, 11 Aug 2016 10:48:44 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Icenowy Zheng <icenowy@...c.xyz>
Cc:	Matt Fleming <matt@...eblueprint.co.uk>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H . Peter Anvin" <hpa@...or.com>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/efi-bgrt: remove the check of the version field


* Icenowy Zheng <icenowy@...c.xyz> wrote:

> 
> 
> 10.08.2016, 20:52, "Ingo Molnar" <mingo@...nel.org>:
> > * Icenowy Zheng <icenowy@...c.xyz> wrote:
> >
> >>  Some broken firmwares have a wrongly filled version field in BGRT table.
> >>  (See http://wiki.osdev.org/Broken_UEFI_implementations )
> >>
> >>  As we know, these firmwares can also provide correct BGRT image, although
> >>  the table is wrong.
> >>
> >>  After removing the check of the version field, the kernel can now extract
> >>  the image correctly, and the information is also correct.
> >>
> >>  Tested on a Thinkpad E531 (68854UC).
> >
> > What's the practical effects of the bug - what problems does a missing
> > /sys/firmware/acpi/bgrt/ cause?
> 
> Currently nothing uses this featues. However, one of my friend is trying to
> develop a splash screen which uses ACPI BGRT, like the splash screen
> of Windows 8 and above.
> Without the directory, there won't be any way to retrieve the vendor splash
> logo.

Ok - please add this information to the changelog.

Acked-by: Ingo Molnar <mingo@...nel.org>

Thanks,

	Ingo