[PATCH v2 5/6] spi: spi-sun4i: sun4i_spi_transfer_one(): add error handling at clock setup

[Jonas Rebmann]

Bail out if clk_get_rate() or clk_set_rate() fail during
sun4i_spi_transfer_one(). This might happen if the clock isn't known yet
or fails to set the requested rate.

This also ensures that mclk_rate is nonzero and can be safely divided by
in a future commit.

Signed-off-by: Jonas Rebmann <jre at pengutronix.de>
---
 drivers/spi/spi-sun4i.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
index ea8be0170fbf..94e1c7bbd632 100644
--- a/drivers/spi/spi-sun4i.c
+++ b/drivers/spi/spi-sun4i.c
@@ -279,9 +279,17 @@ static int sun4i_spi_transfer_one(struct spi_controller *host,
 
 	/* Ensure that we have a parent clock fast enough */
 	mclk_rate = clk_get_rate(sspi->mclk);
+	if (!mclk_rate)
+		return -EINVAL;
+
 	if (mclk_rate < (2 * tfr->speed_hz)) {
-		clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
+		ret = clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
+		if (ret)
+			return ret;
+
 		mclk_rate = clk_get_rate(sspi->mclk);
+		if (!mclk_rate)
+			return -EINVAL;
 	}
 
 	/*

-- 
2.55.0.123.gf60db8d575