currently, composite.c tries to make sure all
functions will start on Alternate Setting zero when
a configuration is set.
I've been considering if that's necessary and even
correct, provided f->set_alt() will, essentially,
initialize all endpoints for that particular
interface.
This will generate a small issue when the proper
SetInterface request comes through. Because all our
endpoints are already enabled, we must disable them
all and complete all their requests with -ECONNRESET,
just to reenable them again and requeue same requests.
It will also generate user-visible errors such as
"spurious" SIGHUP on fd-based functions (like all
serial gadgets) because we break the pipe.
I couldn't find anywhere in the USB Specification
where it requires us to make sure all interfaces start
on Alternate Setting zero. IMHO, we should consider
initial state as UNKNOWN and not rely on that being
zero or anything.
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
Note that this will cause a regression on dwc3 due to its
need for a fifo resize (at least on OMAP5), but that's my
problem anyway and I'm ok taking the heat of fixing it.
drivers/usb/gadget/composite.c | 57 ------------------------------------------
1 file changed, 57 deletions(-)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 2cb1030..5b53440 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -630,63 +630,6 @@ static int set_config(struct usb_composite_dev *cdev,
cdev->config = c;
- /* Initialize all interfaces by setting them to altsetting zero. */
- for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
- struct usb_function *f = c->interface[tmp];
- struct usb_descriptor_header **descriptors;
-
- if (!f)
- break;
-
- /*
- * Record which endpoints are used by the function. This is used
- * to dispatch control requests targeted at that endpoint to the
- * function's setup callback instead of the current
- * configuration's setup callback.
- */
- switch (gadget->speed) {
- case USB_SPEED_SUPER:
- descriptors = f->ss_descriptors;
- break;
- case USB_SPEED_HIGH:
- descriptors = f->hs_descriptors;
- break;
- default:
- descriptors = f->descriptors;
- }
-
- for (; *descriptors; ++descriptors) {
- struct usb_endpoint_descriptor *ep;
- int addr;
-
- if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
- continue;
-
- ep = (struct usb_endpoint_descriptor *)*descriptors;
- addr = ((ep->bEndpointAddress & 0x80) >> 3)
- | (ep->bEndpointAddress & 0x0f);
- set_bit(addr, f->endpoints);
- }
-
- result = f->set_alt(f, tmp, 0);
- if (result < 0) {
- DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
- tmp, f->name, f, result);
-
- reset_config(cdev);
- goto done;
- }
-
- if (result == USB_GADGET_DELAYED_STATUS) {
- DBG(cdev,
- "%s: interface %d (%s) requested delayed status\n",
- __func__, tmp, f->name);
- cdev->delayed_status++;
- DBG(cdev, "delayed_status count %d\n",
- cdev->delayed_status);
- }
- }
-
/* when we return, be sure our power usage is valid */
power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
done:
--
1.7.12.rc2
--
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