drm/radeon/kms: don't read attempt to read bios from VRAM on unposted GPU.

Since the VGA switcheroo, we'd attempt to read the BIOS from VRAM on startup
but on some unposted cards this can cause hangs/crashes.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=28592
(further problem pointed out by agd5f on IGP systems)

Reported-by: Reilithion on #radeon
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index fbba938f80481a422418fc3f095b7eef3519c212..2c92137399995f17d9df664c2ae28aa9ad8bbefa 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -48,6 +48,10 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
        resource_size_t vram_base;
        resource_size_t size = 256 * 1024; /* ??? */
 
+       if (!(rdev->flags & RADEON_IS_IGP))
+               if (!radeon_card_posted(rdev))
+                       return false;
+
        rdev->bios = NULL;
        vram_base = drm_get_resource_start(rdev->ddev, 0);
        bios = ioremap(vram_base, size);