Re: [PATCH] fbdev: Prevent probing generic drivers if a FB is already registered
From: Daniel Vetter <hidden>
Date: 2021-11-11 09:55:07
Also in:
dri-devel, lkml
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 <redacted> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Vetter <redacted> Also Cc: stable@vger.kernel.org? btw time to organize drm-misc commit rights so you can push stuff like this? -Daniel
quoted hunk ↗ jump to hunk
--- 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