If we have multiple instances of hid function, each of
them may have different report descriptor, also their
length may be different.
Currently we are using static hidg_desc varable which
is being filled in hidg_bind(). Then we send its content
to host in hidg_setup() function. This content may
have been already overwriten if another instance
has executed hidg_bind().
Signed-off-by: Krzysztof Opasiak <k.opasiak@xxxxxxxxxxx>
---
drivers/usb/gadget/function/f_hid.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index a2612fb..eeb2dc2 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -437,12 +437,20 @@ static int hidg_setup(struct usb_function *f,
| USB_REQ_GET_DESCRIPTOR):
switch (value >> 8) {
case HID_DT_HID:
+ {
+ struct hid_descriptor hidg_desc_copy = hidg_desc;
+
VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
+ hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
+ hidg_desc_copy.desc[0].wDescriptorLength =
+ cpu_to_le16(hidg->report_desc_length);
+
length = min_t(unsigned short, length,
- hidg_desc.bLength);
- memcpy(req->buf, &hidg_desc, length);
+ hidg_desc_copy.bLength);
+ memcpy(req->buf, &hidg_desc_copy, length);
goto respond;
break;
+ }
case HID_DT_REPORT:
VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
length = min_t(unsigned short, length,
@@ -632,6 +640,10 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+ /*
+ * We can use hidg_desc struct here but we should not relay
+ * that its content won't change after returning from this function.
+ */
hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
hidg_desc.desc[0].wDescriptorLength =
cpu_to_le16(hidg->report_desc_length);
--
1.9.1
--
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