d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Try a bit harder to get the USB device descriptor in case the initial read fails.

Browse Source 
MFC after:		1 week
Sponsored by:		Mellanox Technologies // NVIDIA Networking
This commit is contained in:
Hans Petter Selasky 2020-10-08 11:30:22 +00:00
parent eccb214897
commit c3a38d6c91
1 changed files with 17 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/dev/usb/usb_request.c
View File

@ -1973,9 +1973,23 @@ usbd_setup_device_desc(struct usb_device *udev, struct mtx *mtx)
/* get partial device descriptor, some devices crash on this */
err = usbd_req_get_desc(udev, mtx, NULL, &udev->ddesc,
USB_MAX_IPACKET, USB_MAX_IPACKET, 0, UDESC_DEVICE, 0, 0);
if (err != 0)
break;
if (err != 0) {
DPRINTF("Trying fallback for getting the USB device descriptor\n");
/* try 8 bytes bMaxPacketSize */
udev->ddesc.bMaxPacketSize = 8;
/* get full device descriptor */
err = usbd_req_get_device_desc(udev, mtx, &udev->ddesc);
if (err == 0)
break;
/* try 16 bytes bMaxPacketSize */
udev->ddesc.bMaxPacketSize = 16;
/* get full device descriptor */
err = usbd_req_get_device_desc(udev, mtx, &udev->ddesc);
if (err == 0)
break;
/* try 32/64 bytes bMaxPacketSize */
udev->ddesc.bMaxPacketSize = 32;
}
/* get the full device descriptor */
err = usbd_req_get_device_desc(udev, mtx, &udev->ddesc);
break;