diff mbox series

usb: Flush altsetting 0 endpoints before reinitializating them after reset.

Message ID 20250514132520.225345-1-mathias.nyman@linux.intel.com
State New
Headers show
Series usb: Flush altsetting 0 endpoints before reinitializating them after reset. | expand

Commit Message

Mathias Nyman May 14, 2025, 1:25 p.m. UTC
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@vger.kernel.org
Fixes: 4fe0387afa89 ("USB: don't send Set-Interface after reset")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/core/hub.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 0e1dd6ef60a7..9f19fc7494e0 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -6133,6 +6133,7 @@  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;
@@ -6190,6 +6191,18 @@  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) {
@@ -6221,12 +6234,11 @@  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 {