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References: <20210413170508.968148-1-kai.heng.feng@canonical.com>
In-Reply-To: <20210413170508.968148-1-kai.heng.feng@canonical.com>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Tue, 13 Apr 2021 14:01:53 -0400
Message-ID: <CADnq5_P7_7jOZWTo+KCj3jOpmyDPN8eH3jNTgg3xLC4V9QM7kQ@mail.gmail.com>
Subject: Re: [PATCH] efifb: Check efifb_pci_dev before using it
To:     Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc:     pjones@redhat.com,
        "open list:EFIFB FRAMEBUFFER DRIVER" <linux-fbdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:FRAMEBUFFER LAYER" <dri-devel@lists.freedesktop.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Alex Deucher <alexander.deucher@amd.com>
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On Tue, Apr 13, 2021 at 1:05 PM Kai-Heng Feng
<kai.heng.feng@canonical.com> wrote:
>
> On some platforms like Hyper-V and RPi4 with UEFI firmware, efifb is not
> a PCI device.
>
> So make sure efifb_pci_dev is found before using it.
>
> Fixes: a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0")
> BugLink: https://bugs.launchpad.net/bugs/1922403
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

> ---
>  drivers/video/fbdev/efifb.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
> index f58a545b3bf3..8ea8f079cde2 100644
> --- a/drivers/video/fbdev/efifb.c
> +++ b/drivers/video/fbdev/efifb.c
> @@ -575,7 +575,8 @@ static int efifb_probe(struct platform_device *dev)
>                 goto err_fb_dealoc;
>         }
>         fb_info(info, "%s frame buffer device\n", info->fix.id);
> -       pm_runtime_get_sync(&efifb_pci_dev->dev);
> +       if (efifb_pci_dev)
> +               pm_runtime_get_sync(&efifb_pci_dev->dev);
>         return 0;
>
>  err_fb_dealoc:
> @@ -602,7 +603,8 @@ static int efifb_remove(struct platform_device *pdev)
>         unregister_framebuffer(info);
>         sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
>         framebuffer_release(info);
> -       pm_runtime_put(&efifb_pci_dev->dev);
> +       if (efifb_pci_dev)
> +               pm_runtime_put(&efifb_pci_dev->dev);
>
>         return 0;
>  }
> --
> 2.30.2
>
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