IMX6 PCIe external clock on linux kernel 4.14.78

toshihiro_kambe — Wed, 18 Nov 2020 06:08:35 GMT

Hi community

I am using a custom board that design based on NXP i.MX6Q sabreauto board,
and we need to run PCIe device on our custom board.

We modified the devicetree files based on community info, and the challenge was successful.
It was Yocto Daisy(linux kernel 4.1.15) environment.

And this time, we must use Yocto Sumo(linux kernel 4.14.78) environment.
We fixed it the same as 4.1.15, but the result was a failure.
It seems the kernel freeze in kernel starting.

As far as I checked, it seems adding some branches for "ext_osc" and "IMX6QP" in sources.

[drivers/pci/dwc/pci-imx6.c]
>> if (imx_pcie->ext_osc && (imx_pcie->variant == IMX6QP)) {
:
>> if (imx_pcie->variant == IMX6QP) {
:
>> case IMX6QP:

[drivers/clk/imx/clk-imx6q.c]
>> /*
>> * imx6qp sabresd revb board has the external osc used by pcie
>> * - pll6 should be set bypass mode later in driver.
>> * - lvds_clk1 should be selected as pll6 bypass src, set here.
>> */
>> if (clk_on_imx6qp() && val == 1)
>> clk_set_parent(clk[IMX6QDL_PLL6_BYPASS_SRC], clk[IMX6QDL_CLK_LVDS1_IN]);

I tried adding these sequence for "IMX6Q" because of we are using i.MX6Quad chip,
but the situation did not chang. The kernel freeze in kernel starting.

Would you please advice us for using PCIe external clock on linux kernel 4.14.78 ?

Best regards,

Toshihiro Kambe

attached file:

"[OK]PCIe_external_for_Yocto_Daisy_kernel_4_1_15.txt"
"[NG]PCIe_external_for_Yocto_Sumo_kernel_4_14_78.txt"

Re: IMX6 PCIe external clock on linux kernel 4.14.78

weidong_sun — Wed, 09 Dec 2020 06:53:56 GMT

Hi,

See the link, please!

https://community.nxp.com/t5/i-MX-Processors/i-MX6q-PCIe-with-external-clock-and-SATA/m-p/666522?commentID=923849&et=watches.email.thread

check device tree and clock driver in L4.14.78 bsp, please!

In addition, In imx6qp-sabresd-ldo-pcie-cert.dts, external clock has been enabled, you can refer to it for your dts of i.MX6Q/DL board.

Have a nice day!

B.R,

weidong

i.MX SolutionsのトピックIMX6 PCIe external clock on linux kernel 4.14.78

IMX6 PCIe external clock on linux kernel 4.14.78

Re: IMX6 PCIe external clock on linux kernel 4.14.78