From 75e9cf010b41e45ff208300143b8ece89023273b Mon Sep 17 00:00:00 2001
From: Ville Juven <ville.juven@unikie.com>
Date: Thu, 18 Jan 2024 14:54:23 +0200
Subject: [PATCH] mpfs_corespi: Fix firing of stale interrupt after warm reset

After warm reset the interrupt source in the HW block is not explicitly
cleared, thus once the interrupt source is enabled the old / stale interrupt
fires immediately.

This causes a DEBUGASSERT() failure on line 808 mpfs_spi_unload_rx_fifo:
  DEBUGASSERT(nwords > 0);
---
 arch/risc-v/src/mpfs/mpfs_corespi.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/risc-v/src/mpfs/mpfs_corespi.c b/arch/risc-v/src/mpfs/mpfs_corespi.c
index f92ed0123c8e1..e4931f86f7508 100644
--- a/arch/risc-v/src/mpfs/mpfs_corespi.c
+++ b/arch/risc-v/src/mpfs/mpfs_corespi.c
@@ -1435,6 +1435,22 @@ static void mpfs_spi_init(struct spi_dev_s *dev)
   mpfs_spi_set_master_mode(priv, 1);
   mpfs_spi_enable(priv, 1);
 
+  /* Disable all interrupt sources */
+
+  modifyreg32(MPFS_SPI_CONTROL, MPFS_SPI_INTTXTURUN |
+                                MPFS_SPI_INTRXOVRFLOW |
+                                MPFS_SPI_INTTXDONE,
+                                0);
+
+  /* Clear all interrupt sources */
+
+  putreg32(MPFS_SPI_TXCHUNDRUN |
+           MPFS_SPI_RXCHOVRFLW |
+           MPFS_SPI_DATA_RX |
+           MPFS_SPI_TXDONE, MPFS_SPI_INT_CLEAR);
+
+  /* Then enable the interrupt */
+
   up_enable_irq(priv->plic_irq);
 }