dmm/bm52x: silence overzealous compiler warning

[libsigrok.git] / src / scpi / scpi_usbtmc_libusb.c

diff --git a/src/scpi/scpi_usbtmc_libusb.c b/src/scpi/scpi_usbtmc_libusb.c
index 6b0334440e94e9ce993ca534f1b4c58d16abd804..2da67030ed2495c41e9a0c3dcd56f9255d72f201 100644 (file)
--- a/src/scpi/scpi_usbtmc_libusb.c
+++ b/src/scpi/scpi_usbtmc_libusb.c
@@ -107,6 +107,7 @@ static struct usbtmc_blacklist blacklist_remote[] = {
        { 0x1ab1, 0x0588 }, /* Rigol DS1000 series */
        { 0x1ab1, 0x04b0 }, /* Rigol DS2000 series */
        { 0x1ab1, 0x04b1 }, /* Rigol DS4000 series */
+       { 0x1ab1, 0x0515 }, /* Rigol MSO5000 series */
        { 0x0957, 0x0588 }, /* Agilent DSO1000 series (rebadged Rigol DS1000) */
        { 0x0b21, 0xffff }, /* All Yokogawa devices */
        { 0xf4ec, 0xffff }, /* All Siglent SDS devices */
@@ -523,14 +524,36 @@ static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
                                     uint8_t *transfer_attributes)
 {
        struct sr_usb_dev_inst *usb = uscpi->usb;
-       int ret, transferred, message_size;
+       int ret, transferred, message_size, tries;
+
+       for (tries = 0; ; tries++) {
+               ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data,
+                                          size, &transferred,
+                                          TRANSFER_TIMEOUT);
+               if (ret < 0) {
+                       sr_err("USBTMC bulk in transfer error: %s.",
+                              libusb_error_name(ret));
+                       return SR_ERR;
+               }
 
-       ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
-                                  &transferred, TRANSFER_TIMEOUT);
-       if (ret < 0) {
-               sr_err("USBTMC bulk in transfer error: %s.",
-                      libusb_error_name(ret));
-               return SR_ERR;
+               if (transferred == 0 && tries < 1) {
+                       /*
+                        * The DEV_DEP_MSG_IN message is empty, and the TMC
+                        * spec says it should at least contain a header.
+                        * The Rigol DS1054Z seems to do this sometimes, and
+                        * it follows up with a valid message.  Give the device
+                        * one more chance to send a header.
+                        */
+                       sr_warn("USBTMC bulk in start was empty; retrying\n");
+                       continue;
+               }
+
+               if (transferred < USBTMC_BULK_HEADER_SIZE) {
+                       sr_err("USBTMC bulk in returned too little data: %d/%d bytes\n", transferred, size);
+                       return SR_ERR;
+               }
+
+               break;
        }
 
        if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
@@ -670,6 +693,7 @@ static void scpi_usbtmc_libusb_free(void *priv)
 SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
        .name          = "USBTMC",
        .prefix        = "usbtmc",
+       .transport     = SCPI_TRANSPORT_USBTMC,
        .priv_size     = sizeof(struct scpi_usbtmc_libusb),
        .scan          = scpi_usbtmc_libusb_scan,
        .dev_inst_new  = scpi_usbtmc_libusb_dev_inst_new,