[PATCH] USB: bcma: defer probe until USB3 is ready

[Rosen Penev <rosenp@gmail.com>]

Northstar SuperSpeed data goes to xHCI while D+/D- go to EHCI. If EHCI
probes first with VBUS already on, a SuperSpeed device falls back to
high-speed and stays there.

Defer the NS USB2 core until the USB3 core has probed, and enable VBUS
only after that host init (of_platform_populate binds xHCI when
xhci-plat is already registered). USB2-only chips have no NS USB3 core
and are unchanged.

Remove the TODO since checks are being added.

Assisted-by: LLM
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/usb/host/bcma-hcd.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/bcma-hcd.c b/drivers/usb/host/bcma-hcd.c
index 519386255886..9a5704358996 100644
--- a/drivers/usb/host/bcma-hcd.c
+++ b/drivers/usb/host/bcma-hcd.c
@@ -396,8 +396,13 @@ static int bcma_hcd_probe(struct bcma_device *core)
 {
 	int err;
 	struct bcma_hcd_device *usb_dev;
+	struct bcma_device *usb3;
 
-	/* TODO: Probably need checks here; is the core connected? */
+	if (core->id.id == BCMA_CORE_NS_USB20) {
+		usb3 = bcma_find_core(core->bus, BCMA_CORE_NS_USB30);
+		if (usb3 && !bcma_get_drvdata(usb3))
+			return -EPROBE_DEFER;
+	}
 
 	usb_dev = devm_kzalloc(&core->dev, sizeof(struct bcma_hcd_device),
 			       GFP_KERNEL);
-- 
2.55.0