From cfd96cbd607ab5d63a33cd63673221f4d572ea8c Mon Sep 17 00:00:00 2001
From: Stefan Agner <stefan@agner.ch>
Date: Sun, 7 Jan 2018 15:05:49 +0100
Subject: [PATCH] spi: imx: do not access registers while clocks disabled
commit d593574aff0ab846136190b1729c151c736727ec upstream.
Since clocks are disabled except during message transfer clocks
are also disabled when spi_imx_remove gets called. Accessing
registers leads to a freeeze at least on a i.MX 6ULL. Enable
clocks before disabling accessing the MXC_CSPICTRL register.
Fixes: 9e556dcc55774 ("spi: spi-imx: only enable the clocks when we start to transfer a message")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/spi/spi-imx.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index babb15f07995..d51ca243a028 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1496,12 +1496,23 @@ static int spi_imx_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+ int ret;
spi_bitbang_stop(&spi_imx->bitbang);
+ ret = clk_enable(spi_imx->clk_per);
+ if (ret)
+ return ret;
+
+ ret = clk_enable(spi_imx->clk_ipg);
+ if (ret) {
+ clk_disable(spi_imx->clk_per);
+ return ret;
+ }
+
writel(0, spi_imx->base + MXC_CSPICTRL);
- clk_unprepare(spi_imx->clk_ipg);
- clk_unprepare(spi_imx->clk_per);
+ clk_disable_unprepare(spi_imx->clk_ipg);
+ clk_disable_unprepare(spi_imx->clk_per);
spi_imx_sdma_exit(spi_imx);
spi_master_put(master);