From 89bb3dc13ac29a563f4e4c555e422882f64742bd Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Wed, 14 May 2025 16:25:20 +0300 Subject: [PATCH] usb: Flush altsetting 0 endpoints before reinitializating them after reset. usb core avoids sending a Set-Interface altsetting 0 request after device reset, and instead relies on calling usb_disable_interface() and usb_enable_interface() to flush and reset host-side of those endpoints. xHCI hosts allocate and set up endpoint ring buffers and host_ep->hcpriv during usb_hcd_alloc_bandwidth() callback, which in this case is called before flushing the endpoint in usb_disable_interface(). Call usb_disable_interface() before usb_hcd_alloc_bandwidth() to ensure URBs are flushed before new ring buffers for the endpoints are allocated. Otherwise host driver will attempt to find and remove old stale URBs from a freshly allocated new ringbuffer. Cc: stable Fixes: 4fe0387afa89 ("USB: don't send Set-Interface after reset") Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250514132520.225345-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index cfb3abafeacd..416af6d76374 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -6137,6 +6137,7 @@ static int usb_reset_and_verify_device(struct usb_device *udev) struct usb_hub *parent_hub; struct usb_hcd *hcd = bus_to_hcd(udev->bus); struct usb_device_descriptor descriptor; + struct usb_interface *intf; struct usb_host_bos *bos; int i, j, ret = 0; int port1 = udev->portnum; @@ -6194,6 +6195,18 @@ static int usb_reset_and_verify_device(struct usb_device *udev) if (!udev->actconfig) goto done; + /* + * Some devices can't handle setting default altsetting 0 with a + * Set-Interface request. Disable host-side endpoints of those + * interfaces here. Enable and reset them back after host has set + * its internal endpoint structures during usb_hcd_alloc_bandwith() + */ + for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { + intf = udev->actconfig->interface[i]; + if (intf->cur_altsetting->desc.bAlternateSetting == 0) + usb_disable_interface(udev, intf, true); + } + mutex_lock(hcd->bandwidth_mutex); ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL); if (ret < 0) { @@ -6225,12 +6238,11 @@ static int usb_reset_and_verify_device(struct usb_device *udev) */ for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { struct usb_host_config *config = udev->actconfig; - struct usb_interface *intf = config->interface[i]; struct usb_interface_descriptor *desc; + intf = config->interface[i]; desc = &intf->cur_altsetting->desc; if (desc->bAlternateSetting == 0) { - usb_disable_interface(udev, intf, true); usb_enable_interface(udev, intf, true); ret = 0; } else { -- 2.25.1