[PATCH v3] usb: host: xhci-plat: Assign shared_hcd->rsrc_start

[WangYuli]

When inserting a USB device, examining hcd->rsrc_start can be
helpful in identifying which hcd is mounted, as the physical
address represented here is typically unique.

The following code snippet demonstrates this:
  struct usb_hcd *hcd = bus_to_hcd(udev->bus);
  unsigned long long usb_hcd_addr = (unsigned long long)hcd->rsrc_start;

However, this approach has limitations now. For USB hosts with an
MMIO interface, the effectiveness of this method is restricted to
USB 2.0.

Because commit 3429e91a661e ("usb: host: xhci: add platform driver
support") assigned res->start to hcd->rsrc_start. But
shared_hcd->rsrc_start remains unassigned, which is also necessary
in certain scenarios.

Fixes: 3429e91a661e ("usb: host: xhci: add platform driver support")
Co-developed-by: Xu Rao <raoxu@xxxxxxxxxxxxx>
Signed-off-by: Xu Rao <raoxu@xxxxxxxxxxxxx>
Signed-off-by: WangYuli <wangyuli@xxxxxxxxxxxxx>
--
Changlog:
 *v1 -> v2: Move code changes for commit e0fe986972f5 ("usb: host:
xhci-plat: prepare operation w/o shared hcd").
  v2 -> v3: Add the "Fixes" tag and fix a typo in commit message.
---
 drivers/usb/host/xhci-plat.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index e6c9006bd568..457e839b9b53 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -329,6 +329,8 @@ int xhci_plat_probe(struct platform_device *pdev, struct device *sysdev, const s
 		usb3_hcd->can_do_streams = 1;
 
 	if (xhci->shared_hcd) {
+		xhci->shared_hcd->rsrc_start = hcd->rsrc_start;
+		xhci->shared_hcd->rsrc_len = hcd->rsrc_len;
 		ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
 		if (ret)
 			goto put_usb3_hcd;
-- 
2.47.1