Subject: [PATCH 1/3] ARM: imx6sx: Set PLL2 as parent of QSPI clocks

From: [email-masked] (Shawn Guo)
Date: Tue, 16 Dec 2014 15:29:22 +0800

On Fri, Dec 05, 2014 at 12:13:20PM -0200, Fabio Estevam wrote:
> From: Fabio Estevam <[email-masked]>
> 
> Provide a proper parent for QSPI clocks to avoid a kernel oops:
> 
> [    1.037920] Division by zero in kernel.

What is the original parent clock, and how does that cause a division by
zero error?

Shawn

> [    1.041807] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc7-next-20141204-00002-g5aa23e1 #2143
> [    1.050967] Hardware name: Freescale i.MX6 SoloX (Device Tree)
> [    1.056853] Backtrace:
> [    1.059360] [<80011ea0>] (dump_backtrace) from [<8001203c>] (show_stack+0x18/0x1c)
> [    1.066982]  r6:00000000 r5:00000000 r4:00000000 r3:00000000
> [    1.072754] [<80012024>] (show_stack) from [<806b7100>] (dump_stack+0x88/0xa4)
> [    1.080038] [<806b7078>] (dump_stack) from [<80011d20>] (__div0+0x18/0x20)
> [    1.086958]  r5:be018500 r4:be017c00
> [    1.090600] [<80011d08>] (__div0) from [<802aa418>] (Ldiv0+0x8/0x10)
> [    1.097012] [<80504fbc>] (clk_divider_set_rate) from [<80503ddc>] (clk_change_rate+0x14c/0x17c)
> [    1.105759]  r7:00000000 r6:00000000 r5:be018500 r4:00000000
> [    1.111516] [<80503c90>] (clk_change_rate) from [<80503ea0>] (clk_set_rate+0x94/0x98)
> [    1.119391]  r8:be7e0368 r7:00000000 r6:be11a000 r5:be018500 r4:00000000 r3:00000000
> [    1.127290] [<80503e0c>] (clk_set_rate) from [<80410558>] (fsl_qspi_probe+0x23c/0x75c)
> [    1.135260]  r5:be11a010 r4:be350010
> [    1.138900] [<8041031c>] (fsl_qspi_probe) from [<80385a18>] (platform_drv_probe+0x50/0xac)
> 
> Signed-off-by: Fabio Estevam <[email-masked]>
> ---
>  arch/arm/mach-imx/clk-imx6sx.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm/mach-imx/clk-imx6sx.c b/arch/arm/mach-imx/clk-imx6sx.c
> index 17354a1..5a3e5a1 100644
> --- a/arch/arm/mach-imx/clk-imx6sx.c
> +++ b/arch/arm/mach-imx/clk-imx6sx.c
> @@ -558,6 +558,9 @@ static void __init imx6sx_clocks_init(struct device_node *ccm_node)
>  	clk_set_parent(clks[IMX6SX_CLK_GPU_CORE_SEL], clks[IMX6SX_CLK_PLL3_PFD0]);
>  	clk_set_parent(clks[IMX6SX_CLK_GPU_AXI_SEL], clks[IMX6SX_CLK_PLL3_PFD0]);
>  
> +	clk_set_parent(clks[IMX6SX_CLK_QSPI1_SEL], clks[IMX6SX_CLK_PLL2_BUS]);
> +	clk_set_parent(clks[IMX6SX_CLK_QSPI2_SEL], clks[IMX6SX_CLK_PLL2_BUS]);
> +
>  	/* Set initial power mode */
>  	imx6q_set_lpm(WAIT_CLOCKED);
>  }
> -- 
> 1.9.1
>