From 1669dc40d19d12c5470d091b34bd8f9ff06c1944 Mon Sep 17 00:00:00 2001
From: Andrew <yinziyuan@espressif.com>
Date: Tue, 26 Nov 2019 13:11:48 +0800
Subject: [PATCH] spi_slave.c:fix DMA channel set to zero which might gets
 conflict with assert

close #2740
---
 components/driver/spi_slave.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/driver/spi_slave.c b/components/driver/spi_slave.c
index f4eddb1665..e8794149f6 100644
--- a/components/driver/spi_slave.c
+++ b/components/driver/spi_slave.c
@@ -218,7 +218,7 @@ cleanup:
     free(spihost[host]);
     spihost[host] = NULL;
     spicommon_periph_free(host);
-    spicommon_dma_chan_free(dma_chan);
+    if (dma_chan != 0) spicommon_dma_chan_free(dma_chan);
     return ret;
 }