[PATCH] usb: xhci: Fix bNbrPorts overwritten by another controller

[m13738176232]

For the `struct descriptor`, only the `hub` part (`bNbrPorts` and `wHubCharacteristics`) is different for each controller; the other five members (device, config, interface, endpoint,ep_companion)are identical for all XHCI root hubs.

My previous patch only fixed the dynamic reading of `bNbrPorts`, but `wHubCharacteristics` is also different for each controller and will be overridden by the last controller.

New patch as below for referrence.

Signed-off-by: Beibei Yang <13738176232 at 163.com>

Index: drivers/usb/host/xhci.c
===================================================================
--- drivers/usb/host/xhci.c     (revision 10446)
+++ drivers/usb/host/xhci.c     (working copy)
@@ -954,13 +954,7 @@
               case USB_DT_HUB:
               case USB_DT_SS_HUB:
                       debug("USB_DT_HUB config\n");
-                       srcptr = &descriptor.hub;
+                       srcptr = &ctrl->hub_desc;
                       srclen = 0x8;
                       break;
               default:
@@ -1221,20 +1215,21 @@
               return -ENOMEM;

       reg = xhci_readl(&hccr->cr_hcsparams1);
-       descriptor.hub.bNbrPorts = ((reg & HCS_MAX_PORTS_MASK) >>
-                                               HCS_MAX_PORTS_SHIFT);
-       printf("Register %x NbrPorts %d\n", reg, descriptor.hub.bNbrPorts);
+       ctrl->hub_desc = descriptor.hub;
+       ctrl->hub_desc.bNbrPorts = ((reg & HCS_MAX_PORTS_MASK) >>
+                                       HCS_MAX_PORTS_SHIFT);
+       printf("Register %x NbrPorts %d\n", reg, ctrl->hub_desc.bNbrPorts);

       /* Port Indicators */
       reg = xhci_readl(&hccr->cr_hccparams);
       if (HCS_INDICATOR(reg))
-               put_unaligned(get_unaligned(&descriptor.hub.wHubCharacteristics)
-                               | 0x80, &descriptor.hub.wHubCharacteristics);
+               put_unaligned(get_unaligned(&ctrl->hub_desc.wHubCharacteristics)
+                               | 0x80, &ctrl->hub_desc.wHubCharacteristics);

       /* Port Power Control */
       if (HCC_PPC(reg))
-               put_unaligned(get_unaligned(&descriptor.hub.wHubCharacteristics)
-                               | 0x01, &descriptor.hub.wHubCharacteristics);
+               put_unaligned(get_unaligned(&ctrl->hub_desc.wHubCharacteristics)
+                               | 0x01, &ctrl->hub_desc.wHubCharacteristics);

       if (xhci_start(hcor)) {
               xhci_reset(hcor);
Index: include/usb/xhci.h
===================================================================
--- include/usb/xhci.h  (revision 10446)
+++ include/usb/xhci.h  (working copy)
@@ -21,6 +21,7 @@
#include <asm/io.h>
#include <linux/list.h>
#include <linux/compat.h>
+#include <usb.h>

#define MAX_EP_CTX_NUM         31
#define XHCI_ALIGNMENT         64
@@ -1229,6 +1230,7 @@
       struct xhci_erst_entry entry[ERST_NUM_SEGS];
       struct xhci_scratchpad *scratchpad;
       struct xhci_virt_device *devs[MAX_HC_SLOTS];
+       struct usb_hub_descriptor hub_desc;
       int rootdev;
};




---- Replied Message ----
| From | Marek Vasut<marek.vasut at mailbox.org> |
| Date | 06/28/2026 04:10 |
| To | Beibei Yang<13738176232 at 163.com>、u-boot at lists.denx.de |
| Cc | bmeng.cn at gmail.com |
| Subject | Re: [PATCH] usb: xhci: Fix bNbrPorts overwritten by another controller |
On 6/27/26 2:37 PM, Beibei Yang wrote:
> In a system with multiple XHCI controllers, the global descriptor.hub
> (bNbrPorts) can be overwritten by a later initialized controller,
> causing the root hub of an earlier controller to report wrong port
> numbers.
>
> Fix this by dynamically setting bNbrPorts from the current controller's
> hcsparams1 in the USB_DT_HUB request handler, instead of relying on
> a stale global value.

How about having one descriptor per controller ?

This is probably easily doable in xhci_lowlevel_init() with some
ctrl->hub_desc = kmemdup(descriptor.hub,...); and related tweaks.

What do you think ?