USB: ehci-omap: Fix deferred probe for phy handling

[Tony Lindgren <tony@atomide.com>]

The only case where we can bail out safely without a phy is port_mode
is OMAP_USBHS_PORT_MODE_UNUSED. It used to be that OMAP_EHCI_PORT_MODE_PHY
was optional, but that's not a good assumption. We should already have
"ehci-phy" in all the dts files using OMAP_EHCI_PORT_MODE_PHY.

Note that this fix should not be needed for kernels earlier than v4.19
as that's when we started moving devices to probe with ti-sysc. We now
probe l4 interconnects separately, which can cause deferred probe with
the phy being on a separate l4 interconnect from EHCI.

And old kernels would need to be checked for "ehci-phy" property for
this fix to avoid regressions.

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Johan Hovold <johan@kernel.org>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Roger Quadros <rogerq@ti.com>
Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/usb/host/ehci-omap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c
--- a/drivers/usb/host/ehci-omap.c
+++ b/drivers/usb/host/ehci-omap.c
@@ -159,8 +159,8 @@ static int ehci_hcd_omap_probe(struct platform_device *pdev)
 		/* get the PHY device */
 		phy = devm_usb_get_phy_by_phandle(dev, "phys", i);
 		if (IS_ERR(phy)) {
-			/* Don't bail out if PHY is not absolutely necessary */
-			if (pdata->port_mode[i] != OMAP_EHCI_PORT_MODE_PHY)
+			/* Don't bail out if PHY is unused */
+			if (pdata->port_mode[i] == OMAP_USBHS_PORT_MODE_UNUSED)
 				continue;
 
 			ret = PTR_ERR(phy);