jtag/drivers/cmsis_dap: prevent CDC missdetect as CMSIS-DAP bulk

The autodetection of CMSIS-DAP v2 bulk interface is tricky
as not all adapters conform CMSIS-DAP specs.

If an interface has a string descriptor containing CMSIS-DAP,
then OpenOCD did not insisted on the correct interface class
LIBUSB_CLASS_VENDOR_SPEC.

However the relaxed test caused false autodetection of v2 bulk
interface on some CMSIS-DAP v1 adapters with an additional serial
interface with the string descriptor stupidly containing
CMSIS-DAP text.

Make the test less relaxed, refuse autodetection of the interfaces
with the class number of well known functions including CDC and MSC.

Link: https://sourceforge.net/p/openocd/tickets/368/
Change-Id: I917cb257eb42aab93560cc39c61ec35a60ce52e3
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7279
Tested-by: jenkins
Reviewed-by: SilverFox <yyjdelete@126.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/jtag/drivers/cmsis_dap_usb_bulk.c b/src/jtag/drivers/cmsis_dap_usb_bulk.c
index a738200ea57d878bd35f5ef25c6e873edc24ef19..55b9a558a1ccfb921d7ae90aa0a92ca4b0d2813c 100644 (file)
--- a/src/jtag/drivers/cmsis_dap_usb_bulk.c
+++ b/src/jtag/drivers/cmsis_dap_usb_bulk.c
@@ -262,8 +262,10 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
                                        /* If the interface is reliably identified
                                         * then we need not insist on setting USB class, subclass and protocol
                                         * exactly as the specification requires.
+                                        * Just filter out the well known classes, mainly CDC and MSC.
                                         * At least KitProg3 uses class 0 contrary to the specification */
-                                       if (intf_identified_reliably) {
+                                       if (intf_identified_reliably &&
+                                                       (intf_desc->bInterfaceClass == 0 || intf_desc->bInterfaceClass > 0x12)) {
                                                LOG_WARNING("Using CMSIS-DAPv2 interface %d with wrong class %" PRId8
                                                                  " subclass %" PRId8 " or protocol %" PRId8,
                                                                  interface_num,