linux-kernel - Re: [GIT PULL 0/2] EFI fixes for v4.11

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Date:   Wed, 5 Apr 2017 11:45:34 +0100
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Cc:     Ingo Molnar <mingo@...nel.org>,
        "linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Leif Lindholm <leif.lindholm@...aro.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Eugene Cohen <eugene@...com>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        Peter Jones <pjones@...hat.com>
Subject: Re: [GIT PULL 0/2] EFI fixes for v4.11

On 5 April 2017 at 11:44, Bartlomiej Zolnierkiewicz
<b.zolnierkie@...sung.com> wrote:
> On Wednesday, April 05, 2017 11:14:06 AM Ard Biesheuvel wrote:
>> On 5 April 2017 at 11:08, Bartlomiej Zolnierkiewicz
>> <b.zolnierkie@...sung.com> wrote:
>> >
>> > Hi,
>> >
>> > On Tuesday, April 04, 2017 04:27:42 PM Ard Biesheuvel wrote:
>> >> Hello all,
>> >>
>> >> Please pull these fixes for EFI framebuffer support on ARM/arm64 systems.
>> >>
>> >> The following changes since commit 822f5845f710e57d7e2df1fd1ee00d6e19d334fe:
>> >>
>> >>   efi/esrt: Cleanup bad memory map log messages (2017-03-17 18:53:12 +0000)
>> >>
>> >> are available in the git repository at:
>> >>
>> >>   git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git tags/efi-urgent
>> >>
>> >> for you to fetch changes up to e73c2811538bd36ec1340d01bafdc080af31914e:
>> >>
>> >>   efifb: Avoid reconfiguration of BAR that covers the framebuffer (2017-04-04 15:56:43 +0100)
>> >>
>> >> ----------------------------------------------------------------
>> >> Two fixes related to the EFI framebuffer driver:
>> >> - Ignore Graphics Output Protocol (GOP) implementations that are marked as
>> >>   BLT-only -- the framebuffer base address is invalid in this case, and the
>> >>   Blt() method is not accessible to the kernel.
>> >> - If the GOP framebuffer base address coincides with a memory BAR of a PCI
>> >>   device that has memory decoding enabled, claim the memory resource so that
>> >>   the PCI core will not attempt to move it later on.
>> >>
>> >> ----------------------------------------------------------------
>> >> Ard Biesheuvel (1):
>> >>       efifb: Avoid reconfiguration of BAR that covers the framebuffer
>> >
>> > This patch breaks build if PCI support is not enabled:
>> >
>> > drivers/video/fbdev/efifb.c: In function ‘claim_efifb_bar’:
>> > drivers/video/fbdev/efifb.c:386:2: error: implicit declaration of function ‘pci_claim_resource’ [-Werror=implicit-function-declaration]
>> >
>> > (x86 ifdefs are not enough, the patch should also check for PCI support)
>> >
>> > Also please cc: linux-fbdev mailing list & me on fbdev related patches.
>> >
>>
>> Thanks for the report. The patch was tested successfully on an
>> impressive list of configurations by kbuild test robot, but
>> apparently, none of those has PCI disabled.
>
> Well, it has been found by looking at the patch itself and since
> none of defconfigs contains such configuration currently the issue
> is rather minor one.
>
> [ Also sorry for the late report but this is the first time I see
>   these patches.  They were never posted to linux-fbdev or me. ]
>

Apologies for that. I did cc Peter but no other fbdev maintainers.

>> Ingo, since you have queued this already, how would you like to
>> proceed? I don't think we need anything beyond
>
> I see that Ingo fixed the patch himself so it is all fine now,
> thanks!
>
>> diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
>> index 758960b6aec9..b827a8113e26 100644
>> --- a/drivers/video/fbdev/efifb.c
>> +++ b/drivers/video/fbdev/efifb.c
>> @@ -364,7 +364,7 @@ static struct platform_driver efifb_driver = {
>>
>>  builtin_platform_driver(efifb_driver);
>>
>> -#ifndef CONFIG_X86
>> +#if defined(CONFIG_PCI) && !defined(CONFIG_X86)
>>
>>  static bool pci_bar_found;     /* did we find a BAR matching the efifb base? */
>
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics
>