lkml.org 
[lkml]   [2021]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] fbdev: Prevent probing generic drivers if a FB is already registered
On Thu, Nov 11, 2021 at 10:20:53AM +0100, Javier Martinez Canillas wrote:
> The efifb and simplefb drivers just render to a pre-allocated frame buffer
> and rely on the display hardware being initialized before the kernel boots.
>
> But if another driver already probed correctly and registered a fbdev, the
> generic drivers shouldn't be probed since an actual driver for the display
> hardware is already present.
>
> Reported-by: Ilya Trukhanov <lahvuun@gmail.com>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Also Cc: stable@vger.kernel.org?

btw time to organize drm-misc commit rights so you can push stuff like
this?
-Daniel

> ---
>
> drivers/video/fbdev/efifb.c | 6 ++++++
> drivers/video/fbdev/simplefb.c | 6 ++++++
> 2 files changed, 12 insertions(+)
>
> diff --git drivers/video/fbdev/efifb.c drivers/video/fbdev/efifb.c
> index edca3703b964..76325c07cf0c 100644
> --- drivers/video/fbdev/efifb.c
> +++ drivers/video/fbdev/efifb.c
> @@ -351,6 +351,12 @@ static int efifb_probe(struct platform_device *dev)
> char *option = NULL;
> efi_memory_desc_t md;
>
> + if (num_registered_fb > 0) {
> + dev_err(&dev->dev,
> + "efifb: a framebuffer is already registered\n");
> + return -EINVAL;
> + }
> +
> if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
> return -ENODEV;
>
> diff --git drivers/video/fbdev/simplefb.c drivers/video/fbdev/simplefb.c
> index 62f0ded70681..55c1f54d7663 100644
> --- drivers/video/fbdev/simplefb.c
> +++ drivers/video/fbdev/simplefb.c
> @@ -407,6 +407,12 @@ static int simplefb_probe(struct platform_device *pdev)
> struct simplefb_par *par;
> struct resource *mem;
>
> + if (num_registered_fb > 0) {
> + dev_err(&pdev->dev,
> + "simplefb: a framebuffer is already registered\n");
> + return -EINVAL;
> + }
> +
> if (fb_get_options("simplefb", NULL))
> return -ENODEV;
>
> --
> 2.33.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

\
 
 \ /
  Last update: 2021-11-11 10:56    [W:0.092 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site