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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2018-03-23 13:44:06 +1100
committerFelipe Balbi <felipe.balbi@linux.intel.com>2018-03-23 09:51:43 +0200
commitaaeab02ddcc830e31c33cdb72a3c117b2d499ae2 (patch)
treeb18844fb0d090abf753ad32777dcb496a4f0412b
parent2f710c1bb666ffd68ed44db190238d4660766f2d (diff)
usb/gadget: Add an EP dispose() callback for EP lifetime tracking
Some UDC may want to allocate endpoints dynamically, either because the HW supports an arbitrary large number or because (like the Aspeed BMC SoCs), the pool of HW endpoints is shared between multiple gadgets. The allocation side can be done rather easily using the existing match_ep() UDC hook. However we have no good place to "free" them. This implements a "simple" variant of this, which calls an EP dispose callback on all EPs associated with a gadget when the composite device gets unbound. This is required by my upcoming Aspeed vHub driver. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
-rw-r--r--drivers/usb/gadget/composite.c16
-rw-r--r--include/linux/usb/gadget.h1
2 files changed, 17 insertions, 0 deletions
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 1924e20f6e8c..63a7cb87514a 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -2142,6 +2142,7 @@ end:
void composite_dev_cleanup(struct usb_composite_dev *cdev)
{
struct usb_gadget_string_container *uc, *tmp;
+ struct usb_ep *ep, *tmp_ep;
list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
list_del(&uc->list);
@@ -2163,6 +2164,21 @@ void composite_dev_cleanup(struct usb_composite_dev *cdev)
}
cdev->next_string_id = 0;
device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
+
+ /*
+ * Some UDC backends have a dynamic EP allocation scheme.
+ *
+ * In that case, the dispose() callback is used to notify the
+ * backend that the EPs are no longer in use.
+ *
+ * Note: The UDC backend can remove the EP from the ep_list as
+ * a result, so we need to use the _safe list iterator.
+ */
+ list_for_each_entry_safe(ep, tmp_ep,
+ &cdev->gadget->ep_list, ep_list) {
+ if (ep->ops->dispose)
+ ep->ops->dispose(ep);
+ }
}
static int composite_bind(struct usb_gadget *gadget,
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 66a5cff7ee14..e3424234b23a 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -129,6 +129,7 @@ struct usb_ep_ops {
int (*enable) (struct usb_ep *ep,
const struct usb_endpoint_descriptor *desc);
int (*disable) (struct usb_ep *ep);
+ void (*dispose) (struct usb_ep *ep);
struct usb_request *(*alloc_request) (struct usb_ep *ep,
gfp_t gfp_flags);