kingst-la2016: use a pool of USB bulk transfers, speedup download

Use a pool of 32 USB bulk transfers of up to 256KiB size each. Which
doubles throughput and reduces the time to download the capture data
after acquisition has completed.

diff --git a/src/hardware/kingst-la2016/protocol.c b/src/hardware/kingst-la2016/protocol.c
index 3ade5be5ecebc570cd73b0b42a0899afcec1fbe8..36625258e4819038c45f0a5a632b6ccdf6c74938 100644 (file)
--- a/src/hardware/kingst-la2016/protocol.c
+++ b/src/hardware/kingst-la2016/protocol.c
@@ -945,23 +945,26 @@ SR_PRIV int la2016_upload_firmware(const struct sr_dev_inst *sdi,
 
 static void LIBUSB_CALL receive_transfer(struct libusb_transfer *xfer);
 
+static void la2016_usbxfer_release_cb(gpointer p)
+{
+       struct libusb_transfer *xfer;
+
+       xfer = p;
+       g_free(xfer->buffer);
+       libusb_free_transfer(xfer);
+}
+
 static int la2016_usbxfer_release(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       struct libusb_transfer *xfer;
 
        devc = sdi ? sdi->priv : NULL;
        if (!devc)
                return SR_ERR_ARG;
 
        /* Release all USB transfers. */
-       xfer = devc->transfer;
-       devc->transfer = NULL;
-       if (!xfer)
-               return SR_OK;
-
-       g_free(xfer->buffer);
-       libusb_free_transfer(xfer);
+       g_slist_free_full(devc->transfers, la2016_usbxfer_release_cb);
+       devc->transfers = NULL;
 
        return SR_OK;
 }
@@ -969,7 +972,7 @@ static int la2016_usbxfer_release(const struct sr_dev_inst *sdi)
 static int la2016_usbxfer_allocate(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       size_t bufsize;
+       size_t bufsize, xfercount;
        uint8_t *buffer;
        struct libusb_transfer *xfer;
 
@@ -978,7 +981,7 @@ static int la2016_usbxfer_allocate(const struct sr_dev_inst *sdi)
                return SR_ERR_ARG;
 
        /* Transfers were already allocated before? */
-       if (devc->transfer)
+       if (devc->transfers)
                return SR_OK;
 
        /*
@@ -992,19 +995,22 @@ static int la2016_usbxfer_allocate(const struct sr_dev_inst *sdi)
         * required in this location.
         */
        bufsize = LA2016_USB_BUFSZ;
-       buffer = g_try_malloc(bufsize);
-       if (!buffer) {
-               sr_err("Cannot allocate USB transfer buffer.");
-               return SR_ERR_MALLOC;
-       }
-       xfer = libusb_alloc_transfer(0);
-       if (!xfer) {
-               sr_err("Cannot allocate USB transfer.");
-               g_free(buffer);
-               return SR_ERR_MALLOC;
-       }
-       xfer->buffer = buffer;
-       devc->transfer = xfer;
+       xfercount = LA2016_USB_XFER_COUNT;
+       while (xfercount--) {
+               buffer = g_try_malloc(bufsize);
+               if (!buffer) {
+                       sr_err("Cannot allocate USB transfer buffer.");
+                       return SR_ERR_MALLOC;
+               }
+               xfer = libusb_alloc_transfer(0);
+               if (!xfer) {
+                       sr_err("Cannot allocate USB transfer.");
+                       g_free(buffer);
+                       return SR_ERR_MALLOC;
+               }
+               xfer->buffer = buffer;
+               devc->transfers = g_slist_append(devc->transfers, xfer);
+       }
        devc->transfer_bufsize = bufsize;
 
        return SR_OK;
@@ -1013,6 +1019,7 @@ static int la2016_usbxfer_allocate(const struct sr_dev_inst *sdi)
 static int la2016_usbxfer_cancel_all(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
+       GSList *l;
        struct libusb_transfer *xfer;
 
        devc = sdi ? sdi->priv : NULL;
@@ -1020,9 +1027,12 @@ static int la2016_usbxfer_cancel_all(const struct sr_dev_inst *sdi)
                return SR_ERR_ARG;
 
        /* Unconditionally cancel the transfer. Ignore errors. */
-       xfer = devc->transfer;
-       if (xfer)
+       for (l = devc->transfers; l; l = l->next) {
+               xfer = l->data;
+               if (!xfer)
+                       continue;
                libusb_cancel_transfer(xfer);
+       }
 
        return SR_OK;
 }
@@ -1061,15 +1071,22 @@ static int la2016_usbxfer_resubmit(const struct sr_dev_inst *sdi,
 static int la2016_usbxfer_submit_all(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
+       GSList *l;
+       struct libusb_transfer *xfer;
        int ret;
 
        devc = sdi ? sdi->priv : NULL;
        if (!devc)
                return SR_ERR_ARG;
 
-       ret = la2016_usbxfer_resubmit(sdi, devc->transfer);
-       if (ret != SR_OK)
-               return ret;
+       for (l = devc->transfers; l; l = l->next) {
+               xfer = l->data;
+               if (!xfer)
+                       return SR_ERR_ARG;
+               ret = la2016_usbxfer_resubmit(sdi, xfer);
+               if (ret != SR_OK)
+                       return ret;
+       }
 
        return SR_OK;
 }

diff --git a/src/hardware/kingst-la2016/protocol.h b/src/hardware/kingst-la2016/protocol.h
index c536617fcd47aaba97f4b44e75dc170c768cedec..bbb44c336a8edcf7541b392aa47fa3d3a665b7ba 100644 (file)
--- a/src/hardware/kingst-la2016/protocol.h
+++ b/src/hardware/kingst-la2016/protocol.h
@@ -46,6 +46,7 @@
  */
 #define LA2016_EP6_PKTSZ       512 /* Max packet size of USB endpoint 6. */
 #define LA2016_USB_BUFSZ       (256 * 2 * LA2016_EP6_PKTSZ) /* 256KiB buffer. */
+#define LA2016_USB_XFER_COUNT  32 /* Size of USB bulk transfers pool. */
 
 /* USB communication timeout during regular operation. */
 #define DEFAULT_TIMEOUT_MS     200
@@ -148,7 +149,7 @@ struct dev_context {
        uint32_t read_pos;
 
        struct feed_queue_logic *feed_queue;
-       struct libusb_transfer *transfer;
+       GSList *transfers;
        size_t transfer_bufsize;
 };