[PATCH] rivafb/nvidiafb: race between register_framebuffer and *_bl_init

Since we now use the generic backlight infrastructure, I think we need to
call rivafb_bl_init before calling register_framebuffer since otherwise
rivafb_bl_init might race with the framebuffer layer already opening the
device and setting up the video mode.  In this case we might end up with a
not yet fully intialized backlight (info->bl_dev still NULL) when calling
riva_bl_set_power via rivafb_set_par/rivafb_load_video_mode and the kernel
dies without any further notice during boot.

This fixes booting current git on a PB 6,1.  In this case radeonfb/atyfb
would be affected too - I can fix that too but don't have any hardware to
test this on.

Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 5 insertions, 7 deletions

diff --git a/drivers/video/nvidia/nvidia.c b/drivers/video/nvidia/nvidia.c
index d0ca0d89dd2a..d4f850117874 100644
--- a/drivers/video/nvidia/nvidia.c
+++ b/drivers/video/nvidia/nvidia.c
@@ -1299,20 +1299,19 @@ static int __devinit nvidiafb_probe(struct pci_dev *pd,
 
         nvidia_save_vga(par, &par->SavedReg);
 
+        pci_set_drvdata(pd, info);
+        nvidia_bl_init(par);
         if (register_framebuffer(info) < 0) {
                 printk(KERN_ERR PFX "error registering nVidia framebuffer\n");
                 goto err_out_iounmap_fb;
         }
 
-        pci_set_drvdata(pd, info);
 
         printk(KERN_INFO PFX
                "PCI nVidia %s framebuffer (%dMB @ 0x%lX)\n",
                info->fix.id,
                par->FbMapSize / (1024 * 1024), info->fix.smem_start);
 
-        nvidia_bl_init(par);
-
         NVTRACE_LEAVE();
         return 0;
 
diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c
index 33dddbae5420..76fc9d355eb7 100644
--- a/drivers/video/riva/fbdev.c
+++ b/drivers/video/riva/fbdev.c
@@ -2132,6 +2132,9 @@ static int __devinit rivafb_probe(struct pci_dev *pd,
 
         fb_destroy_modedb(info->monspecs.modedb);
         info->monspecs.modedb = NULL;
+
+        pci_set_drvdata(pd, info);
+        riva_bl_init(info->par);
         ret = register_framebuffer(info);
         if (ret < 0) {
                 printk(KERN_ERR PFX
@@ -2139,8 +2142,6 @@ static int __devinit rivafb_probe(struct pci_dev *pd,
                 goto err_iounmap_screen_base;
         }
 
-        pci_set_drvdata(pd, info);
-
         printk(KERN_INFO PFX
                 "PCI nVidia %s framebuffer ver %s (%dMB @ 0x%lX)\n",
                 info->fix.id,
@@ -2148,8 +2149,6 @@ static int __devinit rivafb_probe(struct pci_dev *pd,
                 info->fix.smem_len / (1024 * 1024),
                 info->fix.smem_start);
 
-        riva_bl_init(info->par);
-
         NVTRACE_LEAVE();
         return 0;