From 1e99226fd96a4c90113c819e7d9db29679210085 Mon Sep 17 00:00:00 2001
From: Eric Katzfey <eric.katzfey@modalai.com>
Date: Wed, 13 Nov 2024 16:36:53 -0800
Subject: [PATCH] AP_HAL_QURT: Fix the SPI transfer special case where a send
 buffer is passed in even though it is a read transaction.

---
 libraries/AP_HAL_QURT/SPIDevice.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libraries/AP_HAL_QURT/SPIDevice.cpp b/libraries/AP_HAL_QURT/SPIDevice.cpp
index 616cf6a76f..a4fcdc6660 100644
--- a/libraries/AP_HAL_QURT/SPIDevice.cpp
+++ b/libraries/AP_HAL_QURT/SPIDevice.cpp
@@ -67,6 +67,12 @@ bool SPIDevice::transfer(const uint8_t *send, uint32_t send_len,
         return transfer_fullduplex(send, (uint8_t*) send, send_len);
     }
 
+    // Special case handling. This can happen when a send buffer is specified
+    // even though we are doing only a read.
+    if (send == recv && send_len == recv_len) {
+        return transfer_fullduplex(send, recv, send_len);
+    }
+
     // This is a read transaction
     uint8_t buf[send_len+recv_len];
     if (send_len > 0) {