[PATCH] clk: imx6ull: use OSC clock during AXI rate change

From: Stefan Agner
Date: Wed Apr 18 2018 - 08:49:24 EST


On i.MX6 ULL using PLL3 seems to cause a freeze when setting
the parent to IMX6UL_CLK_PLL3_USB_OTG. This only seems to appear
since commit 6f9575e55632 ("clk: imx: Add CLK_IS_CRITICAL flag
for busy divider and busy mux"), probably because the clock is
now forced to be on.

Fixes: 6f9575e55632("clk: imx: Add CLK_IS_CRITICAL flag for busy divider and busy mux")
Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
---
This addresses a regression ssen on v4.17-rc1 where the kernel
boots during clock initialization, see also:
https://patchwork.kernel.org/patch/10295927/

drivers/clk/imx/clk-imx6ul.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/imx/clk-imx6ul.c b/drivers/clk/imx/clk-imx6ul.c
index 114ecbb94ec5..12320118f8de 100644
--- a/drivers/clk/imx/clk-imx6ul.c
+++ b/drivers/clk/imx/clk-imx6ul.c
@@ -464,7 +464,7 @@ static void __init imx6ul_clocks_init(struct device_node *ccm_node)
clk_set_rate(clks[IMX6UL_CLK_AHB], 99000000);

/* Change periph_pre clock to pll2_bus to adjust AXI rate to 264MHz */
- clk_set_parent(clks[IMX6UL_CLK_PERIPH_CLK2_SEL], clks[IMX6UL_CLK_PLL3_USB_OTG]);
+ clk_set_parent(clks[IMX6UL_CLK_PERIPH_CLK2_SEL], clks[IMX6UL_CLK_OSC]);
clk_set_parent(clks[IMX6UL_CLK_PERIPH], clks[IMX6UL_CLK_PERIPH_CLK2]);
clk_set_parent(clks[IMX6UL_CLK_PERIPH_PRE], clks[IMX6UL_CLK_PLL2_BUS]);
clk_set_parent(clks[IMX6UL_CLK_PERIPH], clks[IMX6UL_CLK_PERIPH_PRE]);
--
2.17.0