[U-Boot] [PATCH v2] spi: kirkwood: avoid divide by zero crash

[Baruch Siach]

Calling .set_speed with zero speed is definitely a bug. Instead of crashing,
set hz to 1 so that we get the lowest possible frequency rate.

Signed-off-by: Baruch Siach <baruch at tkos.co.il>
---
v2: Don't fail; set lowest rate (Jagan)
---
 drivers/spi/kirkwood_spi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/spi/kirkwood_spi.c b/drivers/spi/kirkwood_spi.c
index 0c6bd295cde9..5744849a5ad9 100644
--- a/drivers/spi/kirkwood_spi.c
+++ b/drivers/spi/kirkwood_spi.c
@@ -257,6 +257,9 @@ static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
 	struct kwspi_registers *reg = plat->spireg;
 	u32 data;
 
+	/* Avoid divide by zero; instead, set the lowest possible speed */
+	if (hz == 0)
+		hz = 1;
 	/* calculate spi clock prescaller using max_hz */
 	data = ((CONFIG_SYS_TCLK / 2) / hz) + 0x10;
 	data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
-- 
2.15.0