USB: ehci-mxc: bail out on transceiver problems

The old code registered the hcd even if there were no transceivers
detected, leading to oopses like this if we try to probe a non-existant
ULPI:

[    2.730000] mxc-ehci mxc-ehci.0: unable to init transceiver
[    2.740000] timeout polling for ULPI device
[    2.740000] timeout polling for ULPI device
[    2.750000] mxc-ehci mxc-ehci.0: unable to enable vbus on transceiver
[    2.750000] mxc-ehci mxc-ehci.0: Freescale On-Chip EHCI Host Controller
[    2.760000] mxc-ehci mxc-ehci.0: new USB bus registered, assigned bus number 2
[    2.770000] Unhandled fault: external abort on non-linefetch (0x808) at 0xc4876184
[    2.770000] Internal error: : 808 [#1] PREEMPT
[    2.770000] last sysfs file:
[    2.770000] Modules linked in:
[    2.770000] CPU: 0    Not tainted  (2.6.33.5 #5)
[    2.770000] PC is at ehci_hub_control+0x4d4/0x8f8
[    2.770000] LR is at ehci_mxc_setup+0xbc/0xdc
[    2.770000] pc : [<c0196dfc>]    lr : [<c019bc8c>]    psr: 00000093
[    2.770000] sp : c3815e40  ip : 00000001  fp : 60000013
[    2.770000] r10: c4876184  r9 : 00000000  r8 : c3814000
[    2.770000] r7 : c391d2cc  r6 : 00000001  r5 : 00000001  r4 : 00000000
[    2.770000] r3 : 80000000  r2 : 00000007  r1 : 80000000  r0 : c4876184
[    2.770000] Flags: nzcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM Segment kernel
[    2.770000] Control: 0005317f  Table: a0004000  DAC: 00000017
[    2.770000] Process swapper (pid: 1, stack limit = 0xc3814270)
...
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: stable <stable@kernel.org>
Acked-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/ehci-mxc.c

@@ -207,10 +207,17 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
 	/* Initialize the transceiver */
 	if (pdata->otg) {
 		pdata->otg->io_priv = hcd->regs + ULPI_VIEWPORT_OFFSET;
-		if (otg_init(pdata->otg) != 0)
-			dev_err(dev, "unable to init transceiver\n");
-		else if (otg_set_vbus(pdata->otg, 1) != 0)
+		ret = otg_init(pdata->otg);
+		if (ret) {
+			dev_err(dev, "unable to init transceiver, probably missing\n");
+			ret = -ENODEV;
+			goto err_add;
+		}
+		ret = otg_set_vbus(pdata->otg, 1);
+		if (ret) {
 			dev_err(dev, "unable to enable vbus on transceiver\n");
+			goto err_add;
+		}
 	}
 
 	priv->hcd = hcd;