radeonfb/aty128fb: Disable broken early resume hook for PowerBooks

radeonfb and aty128fb have a special hook called by the PowerMac platform
code very very early on resume from sleep to bring the screen back. This
is useful for debugging wakup problems, but unfortunately, this also became
a source of problems of its own.

The hook is called extremely early, with interrupts still off, and the code
path involved with that code nowadays rely on things like taking mutexes,
GFP_KERNEL allocations, etc...

In addition, the driver now relies on the PCI core to restore the standard
config space before calling resume which doesn't happen with this early
code path.

I'm keeping the code in but commented out along with a fixup call to
pci_restore_state(). The reason is that I still want to make it easy to
re-enable temporarily to track wake up problems, and it's possible that
I can revive it at some stage if we make sleeping things save to call
in early resume using a system state.

In the meantime, this should fix several reported regressions.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Author: ozbenh

drivers/video/aty/aty128fb.c

@@ -1853,13 +1853,14 @@ static void aty128_bl_exit(struct backlight_device *bd)
  *  Initialisation
  */
 
-#ifdef CONFIG_PPC_PMAC
+#ifdef CONFIG_PPC_PMAC__disabled
 static void aty128_early_resume(void *data)
 {
         struct aty128fb_par *par = data;
 
 	if (try_acquire_console_sem())
 		return;
+	pci_restore_state(par->pdev);
 	aty128_do_resume(par->pdev);
 	release_console_sem();
 }
@@ -1907,7 +1908,14 @@ static int __devinit aty128_init(struct pci_dev *pdev, const struct pci_device_i
 		/* Indicate sleep capability */
 		if (par->chip_gen == rage_M3) {
 			pmac_call_feature(PMAC_FTR_DEVICE_CAN_WAKE, NULL, 0, 1);
+#if 0 /* Disable the early video resume hack for now as it's causing problems, among
+       * others we now rely on the PCI core restoring the config space for us, which
+       * isn't the case with that hack, and that code path causes various things to
+       * be called with interrupts off while they shouldn't. I'm leaving the code in
+       * as it can be useful for debugging purposes
+       */
 			pmac_set_early_video_resume(aty128_early_resume, par);
+#endif
 		}
 
 		/* Find default mode */

drivers/video/aty/radeon_pm.c

@@ -2762,12 +2762,13 @@ int radeonfb_pci_resume(struct pci_dev *pdev)
 	return rc;
 }
 
-#ifdef CONFIG_PPC_OF
+#ifdef CONFIG_PPC_OF__disabled
 static void radeonfb_early_resume(void *data)
 {
         struct radeonfb_info *rinfo = data;
 
 	rinfo->no_schedule = 1;
+	pci_restore_state(rinfo->pdev);
 	radeonfb_pci_resume(rinfo->pdev);
 	rinfo->no_schedule = 0;
 }
@@ -2834,7 +2835,14 @@ void radeonfb_pm_init(struct radeonfb_info *rinfo, int dynclk, int ignore_devlis
 		 */
 		if (rinfo->pm_mode != radeon_pm_none) {
 			pmac_call_feature(PMAC_FTR_DEVICE_CAN_WAKE, rinfo->of_node, 0, 1);
+#if 0 /* Disable the early video resume hack for now as it's causing problems, among
+       * others we now rely on the PCI core restoring the config space for us, which
+       * isn't the case with that hack, and that code path causes various things to
+       * be called with interrupts off while they shouldn't. I'm leaving the code in
+       * as it can be useful for debugging purposes
+       */
 			pmac_set_early_video_resume(radeonfb_early_resume, rinfo);
+#endif
 		}
 
 #if 0