fbdev: atyfb: Check if pll_ops->init_pll failed

commit 7073c7fc8d8ba47194e5fc58fcafc0efe7586e9b upstream.

Actually check the return value from pll_ops->init_pll()
as it can return an error.

If the card's BIOS didn't run because it's not the primary VGA card
the fact that the xclk source is unsupported is printed as shown
below but the driver continues on regardless and on my machine causes
a hard lock up.

[   61.470088] atyfb 0000:03:05.0: enabling device (0080 -> 0083)
[   61.476191] atyfb: using auxiliary register aperture
[   61.481239] atyfb: 3D RAGE XL (Mach64 GR, PCI-33) [0x4752 rev 0x27]
[   61.487569] atyfb: 512K SGRAM (1:1), 14.31818 MHz XTAL, 230 MHz PLL, 83 Mhz MCLK, 63 MHz XCLK
[   61.496112] atyfb: Unsupported xclk source:  5.

Fixes: 1da177e ("Linux-2.6.12-rc2")
Signed-off-by: Daniel Palmer <daniel@0x0f.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulrich Hecht <uli@kernel.org>

Author: fifteenhex

drivers/video/fbdev/aty/atyfb_base.c

@@ -2601,8 +2601,12 @@ static int aty_init(struct fb_info *info)
 		printk("\n");
 	}
 #endif
-	if (par->pll_ops->init_pll)
-		par->pll_ops->init_pll(info, &par->pll);
+	if (par->pll_ops->init_pll) {
+		ret = par->pll_ops->init_pll(info, &par->pll);
+		if (ret)
+			return ret;
+	}
+
 	if (par->pll_ops->resume_pll)
 		par->pll_ops->resume_pll(info, &par->pll);