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From:   Wei Ming Chen <jj251510319013@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     andreyknvl@gmail.com, balbi@kernel.org, gregkh@linuxfoundation.org,
        linux-usb@vger.kernel.org, Wei Ming Chen <jj251510319013@gmail.com>
Subject: [PATCH] usb: gadget: return -EINVAL if no proper ep address available
Date:   Tue,  8 Mar 2022 19:28:32 +0800
Message-Id: <20220308112832.6170-1-jj251510319013@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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If we try to use raw_ioctl_ep_enable() for ep5in on a hardware that
only support from ep1-ep4 for both in and out direction, it will return
-EBUSY originally.

I think it will be more intuitive if we return -EINVAL, Cuz -EBUSY sounds
like ep5in is not available now, but might be available in the future.

Signed-off-by: Wei Ming Chen <jj251510319013@gmail.com>
---
 drivers/usb/gadget/legacy/raw_gadget.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
index d86c3a36441e..b4cc083a7ca6 100644
--- a/drivers/usb/gadget/legacy/raw_gadget.c
+++ b/drivers/usb/gadget/legacy/raw_gadget.c
@@ -758,6 +758,7 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
 	unsigned long flags;
 	struct usb_endpoint_descriptor *desc;
 	struct raw_ep *ep;
+	bool ep_num_matched = false;
 
 	desc = memdup_user((void __user *)value, sizeof(*desc));
 	if (IS_ERR(desc))
@@ -792,6 +793,7 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
 		if (ep->addr != usb_endpoint_num(desc) &&
 				ep->addr != USB_RAW_EP_ADDR_ANY)
 			continue;
+		ep_num_matched = true;
 		if (!usb_gadget_ep_match_desc(dev->gadget, ep->ep, desc, NULL))
 			continue;
 		ep->ep->desc = desc;
@@ -815,6 +817,12 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
 		goto out_unlock;
 	}
 
+	if (!ep_num_matched) {
+		dev_dbg(&dev->gadget->dev, "fail, no proper ep address available\n");
+		ret = -EINVAL;
+		goto out_free;
+	}
+
 	dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
 	ret = -EBUSY;
 
-- 
2.25.1