[PATCH v8 2/5] usb: gadget: configfs: Check USB configuration before adding

From: Wesley Cheng
Date: Wed May 19 2021 - 03:44:17 EST


Ensure that the USB gadget is able to support the configuration being
added based on the number of endpoints required from all interfaces. This
is for accounting for any bandwidth or space limitations.

Signed-off-by: Wesley Cheng <wcheng@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/configfs.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 15a607c..76b9983 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -1374,6 +1374,7 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
struct usb_function *f;
struct usb_function *tmp;
struct gadget_config_name *cn;
+ unsigned long ep_map = 0;

if (gadget_is_otg(gadget))
c->descriptors = otg_desc;
@@ -1403,7 +1404,28 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
list_add(&f->list, &cfg->func_list);
goto err_purge_funcs;
}
+ if (f->fs_descriptors) {
+ struct usb_descriptor_header **d;
+
+ d = f->fs_descriptors;
+ for (; *d; ++d) {
+ struct usb_endpoint_descriptor *ep;
+ int addr;
+
+ if ((*d)->bDescriptorType != USB_DT_ENDPOINT)
+ continue;
+
+ ep = (struct usb_endpoint_descriptor *)*d;
+ addr = ((ep->bEndpointAddress & 0x80) >> 3) |
+ (ep->bEndpointAddress & 0x0f);
+ set_bit(addr, &ep_map);
+ }
+ }
}
+ ret = usb_gadget_check_config(cdev->gadget, ep_map);
+ if (ret)
+ goto err_purge_funcs;
+
usb_ep_autoconfig_reset(cdev->gadget);
}
if (cdev->use_os_string) {
--
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