usb: host: xhci: Notify xHCI sideband on transfer ring free

In the case of handling a USB bus reset, the xhci_discover_or_reset_device
can run without first notifying the xHCI sideband client driver to stop or
prevent the use of the transfer ring.  It was seen that when a bus reset
situation happened, the USB offload driver was attempting to fetch the xHCI
transfer ring information, which was already freed.

Tested-by: Puma Hsu <pumahsu@google.com>
Tested-by: Daehwan Jung <dh10.jung@samsung.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409194804.3773260-6-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Wesley Cheng 2025-04-09 12:47:38 -07:00 committed by Greg Kroah-Hartman
parent 000ab7dab5
commit b85a2ebda1
3 changed files with 60 additions and 2 deletions

View File

@ -88,6 +88,30 @@ __xhci_sideband_remove_endpoint(struct xhci_sideband *sb, struct xhci_virt_ep *e
/* sideband api functions */
/**
* xhci_sideband_notify_ep_ring_free - notify client of xfer ring free
* @sb: sideband instance for this usb device
* @ep_index: usb endpoint index
*
* Notifies the xHCI sideband client driver of a xHCI transfer ring free
* routine. This will allow for the client to ensure that all transfers
* are completed.
*
* The callback should be synchronous, as the ring free happens after.
*/
void xhci_sideband_notify_ep_ring_free(struct xhci_sideband *sb,
unsigned int ep_index)
{
struct xhci_sideband_event evt;
evt.type = XHCI_SIDEBAND_XFER_RING_FREE;
evt.evt_data = &ep_index;
if (sb->notify_client)
sb->notify_client(sb->intf, &evt);
}
EXPORT_SYMBOL_GPL(xhci_sideband_notify_ep_ring_free);
/**
* xhci_sideband_add_endpoint - add endpoint to sideband access list
* @sb: sideband instance for this usb device
@ -342,7 +366,9 @@ EXPORT_SYMBOL_GPL(xhci_sideband_interrupter_id);
* Return: pointer to a new xhci_sideband instance if successful. NULL otherwise.
*/
struct xhci_sideband *
xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type)
xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type,
int (*notify_client)(struct usb_interface *intf,
struct xhci_sideband_event *evt))
{
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
@ -381,6 +407,7 @@ xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type)
sb->vdev = vdev;
sb->intf = intf;
sb->type = type;
sb->notify_client = notify_client;
vdev->sideband = sb;
spin_unlock_irq(&xhci->lock);

View File

@ -20,6 +20,7 @@
#include <linux/string_choices.h>
#include <linux/dmi.h>
#include <linux/dma-mapping.h>
#include <linux/usb/xhci-sideband.h>
#include "xhci.h"
#include "xhci-trace.h"
@ -3919,6 +3920,8 @@ static int xhci_discover_or_reset_device(struct usb_hcd *hcd,
}
if (ep->ring) {
if (ep->sideband)
xhci_sideband_notify_ep_ring_free(ep->sideband, i);
xhci_debugfs_remove_endpoint(xhci, virt_dev, i);
xhci_free_endpoint_ring(xhci, virt_dev, i);
}

View File

@ -21,6 +21,20 @@ enum xhci_sideband_type {
XHCI_SIDEBAND_VENDOR,
};
enum xhci_sideband_notify_type {
XHCI_SIDEBAND_XFER_RING_FREE,
};
/**
* struct xhci_sideband_event - sideband event
* @type: notifier type
* @evt_data: event data
*/
struct xhci_sideband_event {
enum xhci_sideband_notify_type type;
void *evt_data;
};
/**
* struct xhci_sideband - representation of a sideband accessed usb device.
* @xhci: The xhci host controller the usb device is connected to
@ -30,6 +44,7 @@ enum xhci_sideband_type {
* @type: xHCI sideband type
* @mutex: mutex for sideband operations
* @intf: USB sideband client interface
* @notify_client: callback for xHCI sideband sequences
*
* FIXME usb device accessed via sideband Keeping track of sideband accessed usb devices.
*/
@ -44,10 +59,14 @@ struct xhci_sideband {
struct mutex mutex;
struct usb_interface *intf;
int (*notify_client)(struct usb_interface *intf,
struct xhci_sideband_event *evt);
};
struct xhci_sideband *
xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type);
xhci_sideband_register(struct usb_interface *intf, enum xhci_sideband_type type,
int (*notify_client)(struct usb_interface *intf,
struct xhci_sideband_event *evt));
void
xhci_sideband_unregister(struct xhci_sideband *sb);
int
@ -71,4 +90,13 @@ void
xhci_sideband_remove_interrupter(struct xhci_sideband *sb);
int
xhci_sideband_interrupter_id(struct xhci_sideband *sb);
#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND)
void xhci_sideband_notify_ep_ring_free(struct xhci_sideband *sb,
unsigned int ep_index);
#else
static inline void xhci_sideband_notify_ep_ring_free(struct xhci_sideband *sb,
unsigned int ep_index)
{ }
#endif /* IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND) */
#endif /* __LINUX_XHCI_SIDEBAND_H */