jtag/drivers/cmsis_dap: fix usb bulk connection logic 89/5789/7
authorTomas Vanek <vanekt@fbl.cz>
Thu, 30 Jul 2020 08:26:34 +0000 (10:26 +0200)
committerTomas Vanek <vanekt@fbl.cz>
Sun, 15 Nov 2020 21:38:10 +0000 (21:38 +0000)
http://openocd.zylin.com/4831 has following problems in selecting
USB device/interface to connect:
- attempts connection to any device with user class and 2 bulk endpoints
- regardless of cmsis_dap_vid_pid or cmsis_dap_serial setting
  connects to the first suitable device

Distinguish between real match and no filtering cases and use that info
appropriately.

Add debug messages to show why the interface is refused.

Move CMSIS-DAP interface string detection before checking of class/endpoints
to give more understandable debug log in the case the device is refused.

Keep track of reliable matches in both device and interface enumeration.
First search for the interface with CMSIS-DAP in the interface string.
If it fails, chose the first suitable interface.

Change-Id: Ia1aacd5631a9f5c5db580bfb5745ceb6240d61ad
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/5789
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
src/jtag/drivers/cmsis_dap_usb_bulk.c

index b82e3dae560b298ce388f6e7e08fd93cf17607f7..0134c0376557808ab0cdfe28797a13c3a9da5b8a 100644 (file)
@@ -81,7 +81,8 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
 
                /* Match VID/PID */
 
-               bool id_match = true; /* match if we don't enter the loop (no filter) */
+               bool id_match = false;
+               bool id_filter = vids[0] || pids[0];
                for (int id = 0; vids[id] || pids[id]; id++) {
                        id_match = !vids[id] || dev_desc.idVendor == vids[id];
                        id_match &= !pids[id] || dev_desc.idProduct == pids[id];
@@ -90,7 +91,7 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
                                break;
                }
 
-               if (!id_match)
+               if (id_filter && !id_match)
                        continue;
 
                /* Don't continue if we asked for a serial number and the device doesn't have one */
@@ -103,7 +104,7 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
                        /* It's to be expected that most USB devices can't be opened
                         * so only report an error if it was explicitly selected
                         */
-                       if (vids[0] || pids[0]) {
+                       if (id_filter) {
                                LOG_ERROR("could not open device 0x%04x:0x%04x: %s",
                                                dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
                        } else {
@@ -115,7 +116,7 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
 
                /* Match serial number */
 
-               bool serial_match = (serial == NULL);
+               bool serial_match = false;
                char dev_serial[256] = {0};
                if (dev_desc.iSerialNumber > 0) {
                        err = libusb_get_string_descriptor_ascii(
@@ -123,35 +124,44 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
                                        (uint8_t *)dev_serial, sizeof(dev_serial));
 
                        if (err < 0) {
-                               LOG_ERROR("could not read serial number for device 0x%04x:0x%04x: %s",
-                                               dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
+                               const char *msg = "could not read serial number for device 0x%04x:0x%04x: %s";
+                               if (serial)
+                                       LOG_WARNING(msg, dev_desc.idVendor, dev_desc.idProduct,
+                                                               libusb_strerror(err));
+                               else
+                                       LOG_DEBUG(msg, dev_desc.idVendor, dev_desc.idProduct,
+                                                               libusb_strerror(err));
                        } else if (serial && strncmp(dev_serial, serial, sizeof(dev_serial)) == 0) {
                                serial_match = true;
                        }
                }
 
-               if (!serial_match) {
+               if (serial && !serial_match) {
                        libusb_close(dev_handle);
                        continue;
                }
 
                /* Find the CMSIS-DAP string in product string */
 
-               bool cmsis_dap_found = false;
+               bool cmsis_dap_in_product_str = false;
                char product_string[256] = {0};
                if (dev_desc.iProduct > 0) {
                        err = libusb_get_string_descriptor_ascii(
                                        dev_handle, dev_desc.iProduct,
                                        (uint8_t *)product_string, sizeof(product_string));
                        if (err < 0) {
-                               LOG_ERROR("could not read product string for device 0x%04x:0x%04x: %s",
+                               LOG_WARNING("could not read product string for device 0x%04x:0x%04x: %s",
                                                dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
                        } else if (strstr(product_string, "CMSIS-DAP")) {
-                               LOG_DEBUG("CMSIS-DAP found in product string");
-                               cmsis_dap_found = true;
+                               LOG_DEBUG("found product string of 0x%04x:0x%04x '%s'",
+                                                 dev_desc.idVendor, dev_desc.idProduct, product_string);
+                               cmsis_dap_in_product_str = true;
                        }
                }
 
+               bool device_identified_reliably = cmsis_dap_in_product_str
+                                                                                       || serial_match || id_match;
+
                /* Find the CMSIS-DAP interface */
 
                for (int config = 0; config < dev_desc.bNumConfigurations; config++) {
@@ -163,7 +173,11 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
                                continue;
                        }
 
+                       LOG_DEBUG("enumerating interfaces of 0x%04x:0x%04x",
+                                         dev_desc.idVendor, dev_desc.idProduct);
                        int config_num = config_desc->bConfigurationValue;
+                       const struct libusb_interface_descriptor *intf_desc_candidate = NULL;
+                       const struct libusb_interface_descriptor *intf_desc_found = NULL;
 
                        for (int interface = 0; interface < config_desc->bNumInterfaces; interface++) {
                                const struct libusb_interface_descriptor *intf_desc = &config_desc->interface[interface].altsetting[0];
@@ -190,98 +204,165 @@ static int cmsis_dap_usb_open(struct cmsis_dap *dap, uint16_t vids[], uint16_t p
                                 *  - Endpoint 3: Bulk In (optional) – used for streaming SWO trace (if enabled with SWO_STREAM).
                                 */
 
-                               if (intf_desc->bNumEndpoints < 2)
+                               /* Search for "CMSIS-DAP" in the interface string */
+                               bool cmsis_dap_in_interface_str = false;
+                               if (intf_desc->iInterface != 0) {
+
+                                       char interface_str[256] = {0};
+
+                                       err = libusb_get_string_descriptor_ascii(
+                                                       dev_handle, intf_desc->iInterface,
+                                                       (uint8_t *)interface_str, sizeof(interface_str));
+                                       if (err < 0) {
+                                               LOG_DEBUG("could not read interface string %d for device 0x%04x:0x%04x: %s",
+                                                                 intf_desc->iInterface,
+                                                                 dev_desc.idVendor, dev_desc.idProduct,
+                                                                 libusb_strerror(err));
+                                       } else if (strstr(interface_str, "CMSIS-DAP")) {
+                                               cmsis_dap_in_interface_str = true;
+                                               LOG_DEBUG("found interface %d string '%s'",
+                                                                 interface_num, interface_str);
+                                       }
+                               }
+
+                               /* Bypass the following check if this interface was explicitly requested. */
+                               if (cmsis_dap_usb_interface == -1) {
+                                       if (!cmsis_dap_in_product_str && !cmsis_dap_in_interface_str)
+                                               continue;
+                               }
+
+                               /* check endpoints */
+                               if (intf_desc->bNumEndpoints < 2) {
+                                       LOG_DEBUG("skipping interface %d, has only %d endpoints",
+                                                         interface_num, intf_desc->bNumEndpoints);
                                        continue;
+                               }
 
                                if ((intf_desc->endpoint[0].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
-                                               (intf_desc->endpoint[0].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_OUT)
+                                               (intf_desc->endpoint[0].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_OUT) {
+                                       LOG_DEBUG("skipping interface %d, endpoint[0] is not bulk out",
+                                                         interface_num);
                                        continue;
+                               }
 
                                if ((intf_desc->endpoint[1].bmAttributes & 3) != LIBUSB_TRANSFER_TYPE_BULK ||
-                                               (intf_desc->endpoint[1].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_IN)
+                                               (intf_desc->endpoint[1].bEndpointAddress & 0x80) != LIBUSB_ENDPOINT_IN) {
+                                       LOG_DEBUG("skipping interface %d, endpoint[1] is not bulk in",
+                                                         interface_num);
                                        continue;
+                               }
 
-                               /* Bypass the following checks if this interface was explicitly requested. */
-                               if (cmsis_dap_usb_interface == -1) {
-                                       if (intf_desc->bInterfaceClass != LIBUSB_CLASS_VENDOR_SPEC ||
-                                                       intf_desc->bInterfaceSubClass != 0 || intf_desc->bInterfaceProtocol != 0)
+                               /* We can rely on the interface is really CMSIS-DAP if
+                                * - we've seen CMSIS-DAP in the interface string
+                                * - config asked explicitly for an interface number
+                                * - the device has only one interface
+                                * The later two cases should be honored only if we know
+                                * we are on the rigt device */
+                               bool intf_identified_reliably = cmsis_dap_in_interface_str
+                                                       || (device_identified_reliably &&
+                                                                       (cmsis_dap_usb_interface != -1
+                                                                        || config_desc->bNumInterfaces == 1));
+
+                               if (intf_desc->bInterfaceClass != LIBUSB_CLASS_VENDOR_SPEC ||
+                                               intf_desc->bInterfaceSubClass != 0 || intf_desc->bInterfaceProtocol != 0) {
+                                       /* If the interface is reliably identified
+                                        * then we need not insist on setting USB class, subclass and protocol
+                                        * exactly as the specification requires.
+                                        * At least KitProg3 uses class 0 contrary to the specification */
+                                       if (intf_identified_reliably) {
+                                               LOG_WARNING("Using CMSIS-DAPv2 interface %d with wrong class %" PRId8
+                                                                 " subclass %" PRId8 " or protocol %" PRId8,
+                                                                 interface_num,
+                                                                 intf_desc->bInterfaceClass,
+                                                                 intf_desc->bInterfaceSubClass,
+                                                                 intf_desc->bInterfaceProtocol);
+                                       } else {
+                                               LOG_DEBUG("skipping interface %d, class %" PRId8
+                                                                 " subclass %" PRId8 " protocol %" PRId8,
+                                                                 interface_num,
+                                                                 intf_desc->bInterfaceClass,
+                                                                 intf_desc->bInterfaceSubClass,
+                                                                 intf_desc->bInterfaceProtocol);
                                                continue;
 
-                                       /* Search for "CMSIS-DAP" in the interface string */
-                                       if (cmsis_dap_usb_interface != -1 && !cmsis_dap_found) {
-                                               if (intf_desc->iInterface == 0)
-                                                       continue;
-
-                                               char interface_str[256] = {0};
-
-                                               err = libusb_get_string_descriptor_ascii(
-                                                               dev_handle, intf_desc->iInterface,
-                                                               (uint8_t *)interface_str, sizeof(interface_str));
-                                               if (err < 0) {
-                                                       LOG_ERROR("could not read interface string for device 0x%04x:0x%04x: %s",
-                                                                       dev_desc.idVendor, dev_desc.idProduct, libusb_strerror(err));
-                                                       continue;
-                                               } else if (!strstr(interface_str, "CMSIS-DAP")) {
-                                                       continue;
-                                               } else {
-                                                       LOG_DEBUG("CMSIS-DAP found in interface string");
-                                               }
                                        }
                                }
 
-                               int packet_size = intf_desc->endpoint[0].wMaxPacketSize;
-                               int ep_out = intf_desc->endpoint[0].bEndpointAddress;
-                               int ep_in = intf_desc->endpoint[1].bEndpointAddress;
+                               if (intf_identified_reliably) {
+                                       /* That's the one! */
+                                       intf_desc_found = intf_desc;
+                                       break;
+                               }
+
+                               if (!intf_desc_candidate && device_identified_reliably) {
+                                       /* This interface looks suitable for CMSIS-DAP. Store the pointer to it
+                                        * and keep searching for another one with CMSIS-DAP in interface string */
+                                       intf_desc_candidate = intf_desc;
+                               }
+                       }
+
+                       if (!intf_desc_found) {
+                               /* We were not able to identify reliably which interface is CMSIS-DAP.
+                                * Let's use the first suitable if we found one */
+                               intf_desc_found = intf_desc_candidate;
+                       }
 
-                               /* That's the one! */
+                       if (!intf_desc_found) {
                                libusb_free_config_descriptor(config_desc);
-                               libusb_free_device_list(device_list, true);
+                               continue;
+                       }
 
-                               LOG_INFO("Using CMSIS-DAPv2 interface with VID:PID=0x%04x:0x%04x, serial=%s",
-                                               dev_desc.idVendor, dev_desc.idProduct, dev_serial);
+                       /* We've chosen an interface, connect to it */
+                       int interface_num = intf_desc_found->bInterfaceNumber;
+                       int packet_size = intf_desc_found->endpoint[0].wMaxPacketSize;
+                       int ep_out = intf_desc_found->endpoint[0].bEndpointAddress;
+                       int ep_in = intf_desc_found->endpoint[1].bEndpointAddress;
 
-                               int current_config;
-                               err = libusb_get_configuration(dev_handle, &current_config);
-                               if (err) {
-                                       LOG_ERROR("could not find current configuration: %s", libusb_strerror(err));
-                                       libusb_close(dev_handle);
-                                       libusb_exit(ctx);
-                                       return ERROR_FAIL;
-                               }
+                       libusb_free_config_descriptor(config_desc);
+                       libusb_free_device_list(device_list, true);
 
-                               if (config_num != current_config) {
-                                       err = libusb_set_configuration(dev_handle, config_num);
-                                       if (err) {
-                                               LOG_ERROR("could not set configuration: %s", libusb_strerror(err));
-                                               libusb_close(dev_handle);
-                                               libusb_exit(ctx);
-                                               return ERROR_FAIL;
-                                       }
-                               }
+                       LOG_INFO("Using CMSIS-DAPv2 interface with VID:PID=0x%04x:0x%04x, serial=%s",
+                                       dev_desc.idVendor, dev_desc.idProduct, dev_serial);
 
-                               err = libusb_claim_interface(dev_handle, interface_num);
-                               if (err)
-                                       LOG_WARNING("could not claim interface: %s", libusb_strerror(err));
+                       int current_config;
+                       err = libusb_get_configuration(dev_handle, &current_config);
+                       if (err) {
+                               LOG_ERROR("could not find current configuration: %s", libusb_strerror(err));
+                               libusb_close(dev_handle);
+                               libusb_exit(ctx);
+                               return ERROR_FAIL;
+                       }
 
-                               dap->bdata = malloc(sizeof(struct cmsis_dap_backend_data));
-                               if (dap->bdata == NULL) {
-                                       LOG_ERROR("unable to allocate memory");
-                                       libusb_release_interface(dev_handle, interface_num);
+                       if (config_num != current_config) {
+                               err = libusb_set_configuration(dev_handle, config_num);
+                               if (err) {
+                                       LOG_ERROR("could not set configuration: %s", libusb_strerror(err));
                                        libusb_close(dev_handle);
                                        libusb_exit(ctx);
                                        return ERROR_FAIL;
                                }
+                       }
 
-                               dap->packet_size = packet_size + 1; /* "+ 1" for compatibility with the HID backend */
-                               dap->bdata->usb_ctx = ctx;
-                               dap->bdata->dev_handle = dev_handle;
-                               dap->bdata->ep_out = ep_out;
-                               dap->bdata->ep_in = ep_in;
-                               dap->bdata->interface = interface_num;
-                               return ERROR_OK;
+                       err = libusb_claim_interface(dev_handle, interface_num);
+                       if (err)
+                               LOG_WARNING("could not claim interface: %s", libusb_strerror(err));
+
+                       dap->bdata = malloc(sizeof(struct cmsis_dap_backend_data));
+                       if (dap->bdata == NULL) {
+                               LOG_ERROR("unable to allocate memory");
+                               libusb_release_interface(dev_handle, interface_num);
+                               libusb_close(dev_handle);
+                               libusb_exit(ctx);
+                               return ERROR_FAIL;
                        }
 
-                       libusb_free_config_descriptor(config_desc);
+                       dap->packet_size = packet_size + 1; /* "+ 1" for compatibility with the HID backend */
+                       dap->bdata->usb_ctx = ctx;
+                       dap->bdata->dev_handle = dev_handle;
+                       dap->bdata->ep_out = ep_out;
+                       dap->bdata->ep_in = ep_in;
+                       dap->bdata->interface = interface_num;
+                       return ERROR_OK;
                }
 
                libusb_close(dev_handle);

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