From 799f10ea6b495c8b8ad50a5ac2ba7fdd8e42ecd0 Mon Sep 17 00:00:00 2001
From: mark9064 <30447455+mark9064@users.noreply.github.com>
Date: Mon, 15 Dec 2025 23:38:48 +0000
Subject: [PATCH] Split oversized SPI reads

---
 src/drivers/SpiMaster.cpp | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/drivers/SpiMaster.cpp b/src/drivers/SpiMaster.cpp
index 19422ef3c3..5002ea37d0 100644
--- a/src/drivers/SpiMaster.cpp
+++ b/src/drivers/SpiMaster.cpp
@@ -161,6 +161,7 @@ void SpiMaster::OnStartedEvent() {
 }
 
 void SpiMaster::PrepareTx(const uint32_t bufferAddress, const size_t size) {
+  ASSERT(size < 256);
   spiBaseAddress->TXD.PTR = bufferAddress;
   spiBaseAddress->TXD.MAXCNT = size;
   spiBaseAddress->TXD.LIST = 0;
@@ -171,6 +172,7 @@ void SpiMaster::PrepareTx(const uint32_t bufferAddress, const size_t size) {
 }
 
 void SpiMaster::PrepareRx(const uint32_t bufferAddress, const size_t size) {
+  ASSERT(size < 256);
   spiBaseAddress->TXD.PTR = 0;
   spiBaseAddress->TXD.MAXCNT = 0;
   spiBaseAddress->TXD.LIST = 0;
@@ -240,12 +242,17 @@ bool SpiMaster::Read(uint8_t pinCsn, uint8_t* cmd, size_t cmdSize, uint8_t* data
   spiBaseAddress->TASKS_START = 1;
   while (spiBaseAddress->EVENTS_END == 0)
     ;
+  while (dataSize > 0) {
+    size_t readSize = std::min(dataSize, 255U);
+    PrepareRx((uint32_t) data, readSize);
+    spiBaseAddress->TASKS_START = 1;
 
-  PrepareRx((uint32_t) data, dataSize);
-  spiBaseAddress->TASKS_START = 1;
-
-  while (spiBaseAddress->EVENTS_END == 0)
-    ;
+    while (spiBaseAddress->EVENTS_END == 0) {
+      ;
+    }
+    data += readSize;
+    dataSize -= readSize;
+  }
   nrf_gpio_pin_set(this->pinCsn);
 
   xSemaphoreGive(mutex);