linux-kernel - Re: [PATCH] efifb: Ensure graphics device for efifb stays at PCI D0

Open Source and information security mailing list archives

Date:   Mon, 1 Feb 2021 10:21:14 -0500
From:   Alex Deucher <alexdeucher@...il.com>
To:     Kai-Heng Feng <kai.heng.feng@...onical.com>
Cc:     pjones@...hat.com, Hans de Goede <hdegoede@...hat.com>,
        "open list:EFIFB FRAMEBUFFER DRIVER" <linux-fbdev@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:FRAMEBUFFER LAYER" <dri-devel@...ts.freedesktop.org>
Subject: Re: [PATCH] efifb: Ensure graphics device for efifb stays at PCI D0

On Sat, Jan 30, 2021 at 6:27 AM Kai-Heng Feng
<kai.heng.feng@...onical.com> wrote:
>
> We are seeing root ports on some desktop boards support D3cold for
> discrete graphics card. So when efifb is in use while graphics device
> isn't bound to a driver, PCI and ACPI will put the graphics to D3cold
> when runtime suspend kicks in, makes efifb stop working.
>
> So ensure the graphics device won't be runtime suspended, to keep efifb
> work all the time.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@...onical.com>

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

> ---
>  drivers/video/fbdev/efifb.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
> index e57c00824965..19edd7206409 100644
> --- a/drivers/video/fbdev/efifb.c
> +++ b/drivers/video/fbdev/efifb.c
> @@ -16,6 +16,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/printk.h>
>  #include <linux/screen_info.h>
> +#include <linux/pm_runtime.h>
>  #include <video/vga.h>
>  #include <asm/efi.h>
>  #include <drm/drm_utils.h> /* For drm_get_panel_orientation_quirk */
> @@ -575,6 +576,7 @@ 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);
>         return 0;
>
>  err_fb_dealoc:
> @@ -601,6 +603,7 @@ 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);
>
>         return 0;
>  }
> --
> 2.29.2
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

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