Linux 3.14.28 for i.MX6S: Error in imx6q_clocks_init

[armandc_]

Hello,

I'm using the Linux kernel 3.14.28 from Freescale BSP L3.14.28_1.0.0 with a custom board equipped with an i.MX 6 Solo and when booting the kernel I see the following error message:

failed to set parent of clk gpu2d_core_sel to pll2_pfd1_594m: -22

I have traced it down to line 535 in arch/arm/mach-imx/clk-imx6q.c in the imx6q_clocks_init function. I also noticed that this part of the function was changed by commit 93a7adad55.

Is there a fix available?

Best regards,

Armand

[Bio_TICFSL]

Hi Armand,

Please check that  pll2_pfd1_594m is defined for gpu3d_core, while pll2_pfd0_352m, pll2_pfd2_396m are set for 2d_core in case of MX6Solo. the patch is refined from commit 20d89c9c909 and this change kernel imx clock, not gpu-viv.

Hope this helps

[armandc_]

Hello,

I'm a bit confused by your answer. I looked at commit 20d89c9c909 and nothing sets GPU2D_CORE_SEL clock parent.

Shall I change line 535 which sets the parent to PLL2_PFD1_594M:

imx_clk_set_parent(clk[IMX6QDL_CLK_GPU2D_CORE_SEL], clk[IMX6QDL_CLK_PLL2_PFD1_594M]);

by something like that:

imx_clk_set_parent(clk[IMX6QDL_CLK_GPU2D_CORE_SEL], clk[IMX6QDL_CLK_PLL2_PFD0_352M]);

or like this:

imx_clk_set_parent(clk[IMX6QDL_CLK_GPU2D_CORE_SEL], clk[IMX6QDL_CLK_PLL2_PFD2_396M]);

or completely remove the line?

Regards

[sergiobiasi]

Hello,

I also faced this problem on kernel 3.14.38.

Looking at CCM chapter in iMX6Solo/DualLite Reference Manual, in Clock Tree figure you can see that GPU2 could take several clocks but not PLL2_PFD1.

I set the parent to PLL2_PFD2 (IMX6QDL_CLK_PLL2_PFD2_396M) because in the figure there is a dot in the mux and I supposed that is the default.

Regards

[dilshad_alam]

I also faced the same issue. Have you solved this?

[armandc_]

Hello,

Actually not. I'm currently testing the system and I left the error as is. So far it doesn't seem to cause problems but I'm not sure yet and I don't feel confident leaving such an error in a production system. I hope someone at Freescale will answer soon.

Regards,

Armand