From 8a1a5c236d1fc07596a1f23f73e26f24c0e5b540 Mon Sep 17 00:00:00 2001
From: Dave Hylands <dhylands@gmail.com>
Date: Tue, 4 Aug 2015 23:36:01 -0700
Subject: [PATCH] stmhal: Fix hardfault when configured as a SPI slave

---
 stmhal/spi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/stmhal/spi.c b/stmhal/spi.c
index 311f176b3..b1aacfd0b 100644
--- a/stmhal/spi.c
+++ b/stmhal/spi.c
@@ -546,7 +546,9 @@ STATIC mp_obj_t pyb_spi_recv(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_
         if (status == HAL_OK) {
             status = spi_wait_dma_finished(self->spi, args[1].u_int);
         }
-        dma_deinit(&tx_dma);
+        if (self->spi->hdmatx != NULL) {
+            dma_deinit(&tx_dma);
+        }
         dma_deinit(&rx_dma);
     }