rfnoc: compat: Disable DMA FIFO if more radios than DMA channels exist

1 files changed, 31 insertions, 1 deletions

diff --git a/host/lib/rfnoc/legacy_compat.cpp b/host/lib/rfnoc/legacy_compat.cpp
index 137909d8b..31297f271 100644
--- a/host/lib/rfnoc/legacy_compat.cpp
+++ b/host/lib/rfnoc/legacy_compat.cpp
@@ -86,6 +86,36 @@ size_t calc_num_tx_chans_per_radio(
     );
 }
 
+bool check_if_has_dma_fifo(
+        const uhd::device_addr_t &args,
+        uhd::device3::sptr device,
+        uhd::property_tree::sptr tree
+) {
+    if (device->find_blocks(DFIFO_BLOCK_NAME).empty()) {
+        return false;
+    }
+
+    if (args.has_key("skip_dram")) {
+        UHD_LOG_DEBUG("RFNOC",
+                "[legacy_compat] Skipping DRAM at user request.");
+        return false;
+    }
+
+    const size_t num_radios_per_board =
+        device->find_blocks<radio_ctrl>("0/Radio").size();
+    const size_t num_radio_ports = (num_radios_per_board > 0)
+        ?  num_ports(tree, RADIO_BLOCK_NAME, "in")
+        : 0;
+    const size_t num_dmafifo_ports = num_ports(tree, DFIFO_BLOCK_NAME, "in");
+    if (num_dmafifo_ports < num_radios_per_board * num_radio_ports) {
+        UHD_LOG_WARNING("RFNOC",
+            "[legacy_compat] More radio channels than DMA FIFO channels. "
+            "Skipping DMA FIFO.");
+        return false;
+    }
+    return true;
+}
+
 /*! Recreate passed property without bound subscribers. Maintains current property value.
 */
 template <typename T>
@@ -111,7 +141,7 @@ public:
         _tree(device->get_tree()),
         _has_ducs(not args.has_key("skip_duc") and not device->find_blocks(DUC_BLOCK_NAME).empty()),
         _has_ddcs(not args.has_key("skip_ddc") and not device->find_blocks(DDC_BLOCK_NAME).empty()),
-        _has_dmafifo(not args.has_key("skip_dram") and not device->find_blocks(DFIFO_BLOCK_NAME).empty()),
+        _has_dmafifo(check_if_has_dma_fifo(args, device, _tree)),
         _has_sramfifo(not args.has_key("skip_sram") and not device->find_blocks(SFIFO_BLOCK_NAME).empty()),
         _num_mboards(_tree->list("/mboards").size()),
         _num_radios_per_board(device->find_blocks<radio_ctrl>("0/Radio").size()), // These might throw, maybe we catch that and provide a nicer error message.