scpi_usbtmc_libusb: Consistent libusb error handling.

diff --git a/hardware/common/scpi_usbtmc_libusb.c b/hardware/common/scpi_usbtmc_libusb.c
index f66c97285aac56403e8d5d65d7caecf4b64dfbf6..9d96bcca7f2220aedfff5533e586833abfa37524 100644 (file)
--- a/hardware/common/scpi_usbtmc_libusb.c
+++ b/hardware/common/scpi_usbtmc_libusb.c
@@ -102,7 +102,12 @@ static GSList *scpi_usbtmc_libusb_scan(struct drv_context *drvc)
        int confidx, intfidx, ret, i;
        char *res;
 
-       libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
+       ret = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
+       if (ret < 0) {
+               sr_err("Failed to get device list: %s.",
+                      libusb_error_name(ret));
+               return NULL;
+       }
        for (i = 0; devlist[i]; i++) {
                if ((ret = libusb_get_device_descriptor(devlist[i], &des))) {
                        sr_err("Failed to get device descriptor: %s.",
@@ -112,7 +117,8 @@ static GSList *scpi_usbtmc_libusb_scan(struct drv_context *drvc)
 
                for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
                        if (libusb_get_config_descriptor(devlist[i], confidx, &confdes) != 0) {
-                               sr_err("Failed to get configuration descriptor.");
+                               sr_err("Failed to get configuration descriptor: %s.",
+                                      libusb_error_name(ret));
                                break;
                        }
                        for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
@@ -195,7 +201,8 @@ static int scpi_usbtmc_libusb_open(void *priv)
 
        for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
                if (libusb_get_config_descriptor(dev, confidx, &confdes) != 0) {
-                       sr_err("Failed to get configuration descriptor.");
+                       sr_err("Failed to get configuration descriptor: %s.",
+                              libusb_error_name(ret));
                        continue;
                }
                for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
@@ -234,35 +241,49 @@ static int scpi_usbtmc_libusb_open(void *priv)
        }
 
        if (!found) {
-               sr_err("Failed to find USBTMC interface");
+               sr_err("Failed to find USBTMC interface.");
                return SR_ERR;
        }
 
        if (libusb_kernel_driver_active(usb->devhdl, uscpi->interface) == 1) {
                if ((ret = libusb_detach_kernel_driver(usb->devhdl,
                                                       uscpi->interface)) < 0) {
-                       sr_err("failed to detach kernel driver: %s",
-                                       libusb_error_name(ret));
+                       sr_err("Failed to detach kernel driver: %s.",
+                              libusb_error_name(ret));
                        return SR_ERR;
                }
                uscpi->detached_kernel_driver = 1;
        }
 
        if ((ret = libusb_set_configuration(usb->devhdl, config))) {
-               sr_err("Failed to set configuration: %s.", libusb_error_name(ret));
+               sr_err("Failed to set configuration: %s.",
+                      libusb_error_name(ret));
                return SR_ERR;
        }
 
        if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface))) {
-               sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
+               sr_err("Failed to claim interface: %s.",
+                      libusb_error_name(ret));
                return SR_ERR;
        }
 
-       libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep);
-       libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep);
-       libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep);
+       if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0) {
+               sr_err("Failed to clear halt/stall condition for EP %d: %s.",
+                      uscpi->bulk_in_ep, libusb_error_name(ret));
+               return SR_ERR;
+       }
+       if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0) {
+               sr_err("Failed to clear halt/stall condition for EP %d: %s.",
+                      uscpi->bulk_out_ep, libusb_error_name(ret));
+               return SR_ERR;
+       }
+       if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0) {
+               sr_err("Failed to clear halt/stall condition for EP %d: %s.",
+                      uscpi->interrupt_ep, libusb_error_name(ret));
+               return SR_ERR;
+       }
 
-       /* get capabilities */
+       /* Get capabilities. */
        ret = libusb_control_transfer(usb->devhdl,
                                      LIBUSB_ENDPOINT_IN         |
                                      LIBUSB_REQUEST_TYPE_CLASS  |
@@ -276,7 +297,7 @@ static int scpi_usbtmc_libusb_open(void *priv)
                uscpi->usbtmc_dev_cap = capabilities[ 5];
                uscpi->usb488_dev_cap = capabilities[15];
        }
-       sr_dbg("device capabilities: %s%s%s%s%s, %s, %s",
+       sr_dbg("Device capabilities: %s%s%s%s%s, %s, %s",
               uscpi->usb488_dev_cap & USB488_DEV_CAP_SCPI       ? "SCPI, "    : "",
               uscpi->usbtmc_dev_cap & USBTMC_DEV_CAP_TERMCHAR   ? "TermChar, ": "",
               uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY? "L3, " :
@@ -344,12 +365,12 @@ static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
        int padded_size, ret, transferred;
 
        if (data && size+USBTMC_BULK_HEADER_SIZE+3 > (int)sizeof(uscpi->buffer)) {
-               sr_err("USBTMC bulk out transfer too big");
+               sr_err("USBTMC bulk out transfer is too big.");
                return SR_ERR;
        }
 
        uscpi->bTag++;
-       uscpi->bTag += !uscpi->bTag;  /* bTag == 0 is invalid so avoid it */
+       uscpi->bTag += !uscpi->bTag;  /* bTag == 0 is invalid so avoid it. */
 
        usbtmc_bulk_out_header_write(uscpi->buffer, msg_id, uscpi->bTag,
                                     size, transfer_attributes, 0);
@@ -365,12 +386,13 @@ static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
                                   uscpi->buffer, padded_size, &transferred,
                                   TRANSFER_TIMEOUT);
        if (ret) {
-               sr_err("USBTMC bulk out transfer error: %d", ret);
+               sr_err("USBTMC bulk out transfer error: %s.",
+                      libusb_error_name(ret));
                return SR_ERR;
        }
 
        if (transferred < padded_size) {
-               sr_dbg("USBTMC bulkout partial transfer (%d/%d bytes)",
+               sr_dbg("USBTMC bulk out partial transfer (%d/%d bytes).",
                       transferred, padded_size);
                return SR_ERR;
        }
@@ -388,13 +410,14 @@ static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
        ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
                                   &transferred, TRANSFER_TIMEOUT);
        if (ret) {
-               sr_err("USBTMC bulk in transfer error: %d", ret);
+               sr_err("USBTMC bulk in transfer error: %s.",
+                      libusb_error_name(ret));
                return SR_ERR;
        }
 
        if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
                                       transfer_attributes) != SR_OK) {
-               sr_err("USBTMC invalid bulk in header");
+               sr_err("USBTMC invalid bulk in header.");
                return SR_ERR;
        }
 
@@ -415,7 +438,8 @@ static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
        ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
                                   &transferred, TRANSFER_TIMEOUT);
        if (ret) {
-               sr_err("USBTMC bulk in transfer error: %d", ret);
+               sr_err("USBTMC bulk in transfer error: %s.",
+                      libusb_error_name(ret));
                return SR_ERR;
        }
 
@@ -493,18 +517,33 @@ static int scpi_usbtmc_libusb_read_complete(void *priv)
 
 static int scpi_usbtmc_libusb_close(void *priv)
 {
+       int ret;
        struct scpi_usbtmc_libusb *uscpi = priv;
        struct sr_usb_dev_inst *usb = uscpi->usb;
 
        if (!usb->devhdl)
                return SR_ERR;
 
-       libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep);
-       libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep);
-       libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep);
-       libusb_release_interface(usb->devhdl, uscpi->interface);
+       if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_in_ep)) < 0)
+               sr_err("Failed to clear halt/stall condition for EP %d: %s.",
+                      uscpi->bulk_in_ep, libusb_error_name(ret));
+       if ((ret = libusb_clear_halt(usb->devhdl, uscpi->bulk_out_ep)) < 0)
+               sr_err("Failed to clear halt/stall condition for EP %d: %s.",
+                      uscpi->bulk_out_ep, libusb_error_name(ret));
+       if ((ret = libusb_clear_halt(usb->devhdl, uscpi->interrupt_ep)) < 0)
+               sr_err("Failed to clear halt/stall condition for EP %d: %s.",
+                      uscpi->interrupt_ep, libusb_error_name(ret));
+
+       if ((ret = libusb_release_interface(usb->devhdl, uscpi->interface)) < 0)
+               sr_err("Failed to release interface: %s.",
+                      libusb_error_name(ret));
+       
        if (uscpi->detached_kernel_driver) {
-               libusb_attach_kernel_driver(usb->devhdl, uscpi->interface);
+               if ((ret = libusb_attach_kernel_driver(usb->devhdl,
+                                               uscpi->interface)) < 0)
+                       sr_err("Failed to re-attach kernel driver: %s.",
+                              libusb_error_name(ret));
+
                uscpi->detached_kernel_driver = 0;
        }
        libusb_close(usb->devhdl);
@@ -519,7 +558,6 @@ static void scpi_usbtmc_libusb_free(void *priv)
        sr_usb_dev_inst_free(uscpi->usb);
 }
 
-
 SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
        .name          = "USBTMC",
        .prefix        = "usbtmc",