xhci: tegra: fix checked USB2 port number

If USB virtualizatoin is enabled, USB2 ports are shared between all
Virtual Functions. The USB2 port number owned by an USB2 root hub in
a Virtual Function may be less than total USB2 phy number supported
by the Tegra XUSB controller.

Using total USB2 phy number as port number to check all PORTSC values
would cause invalid memory access.

[  116.923438] Unable to handle kernel paging request at virtual address 006c622f7665642f
...
[  117.213640] Call trace:
[  117.216783]  tegra_xusb_enter_elpg+0x23c/0x658
[  117.222021]  tegra_xusb_runtime_suspend+0x40/0x68
[  117.227260]  pm_generic_runtime_suspend+0x30/0x50
[  117.232847]  __rpm_callback+0x84/0x3c0
[  117.237038]  rpm_suspend+0x2dc/0x740
[  117.241229] pm_runtime_work+0xa0/0xb8
[  117.245769]  process_scheduled_works+0x24c/0x478
[  117.251007]  worker_thread+0x23c/0x328
[  117.255547]  kthread+0x104/0x1b0
[  117.259389]  ret_from_fork+0x10/0x20
[  117.263582] Code: 54000222 f9461ae8 f8747908 b4ffff48 (f9400100)

Cc: stable@vger.kernel.org # v6.3+
Fixes: a30951d3 ("xhci: tegra: USB2 pad power controls")
Signed-off-by: Henry Lin <henryl@nvidia.com>
Link: https://lore.kernel.org/r/20241014042134.27664-1-henryl@nvidia.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-tegra.c

@@ -2183,7 +2183,7 @@ static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
 		goto out;
 	}
 
-	for (i = 0; i < tegra->num_usb_phys; i++) {
+	for (i = 0; i < xhci->usb2_rhub.num_ports; i++) {
 		if (!xhci->usb2_rhub.ports[i])
 			continue;
 		portsc = readl(xhci->usb2_rhub.ports[i]->addr);