i.MX ProcessorsのトピックRe: IMX PCIe port link down

IMX PCIe port link down

xiaoqiangyang — Mon, 17 Feb 2014 10:55:43 GMT

Hi all,

I am testing iwl4965 on mini pcie port of MX6Q SABRESD. After linux boot, I can see noting using 'lspci',and I find these messages during boot up:

...

iMX6 PCIe PCIe RC mode imx_pcie_pltfm_probe entering.

PCIE: imx_pcie_pltfm_probe start link up.

link up failed, DB_R0:0x002f0200, DB_R1:0x08200000!

IMX PCIe port: link down!

IMX usb wakeup probe

...

My BSP is L3.0.35_4.1.0_130816 downloaded from freescale,and I add support of pcie in kernel:

System Type --->Freescale MXC Implementations --->[*] PCI Express support

Bus support ---> PCI Express support

Device Drivers ---> Network device support --->Wireless LAN ---> <*> Intel Wireless WiFi 4965AGN (iwl4965)

Adding EC and RC support have no help.

Anyone knows the reason? Are there some places I need pay attention to?

Thanks in advance!

Xiaoqiang

Re: IMX PCIe port link down

wallyyeh — Wed, 19 Feb 2014 07:12:13 GMT

just a suggestion, do you reset your pcie device before you start your kernel?

I do reset in arch/arm/mach-mx6/board-mx6q_sabresd.c

Re: IMX PCIe port link down

minshi — Thu, 07 Apr 2016 02:34:37 GMT

Can you tell me, how do you solve this problem?

Re: IMX PCIe port link down

wallyyeh — Thu, 07 Apr 2016 03:55:50 GMT

I don't even know how to call you, sir. Your name become just a bunch of utf8 codes I guess.

first, this question is not solved since the author never change this question's status.

but if you just want to know "how to reset PCIE device", here's the simple description:

every pcie device must have an reset pin, and most HW design will attach a GPIO on it, what you need is just toggle the GPIO.

hope this will be help.

Re: IMX PCIe port link down

minshi — Thu, 07 Apr 2016 06:17:04 GMT

Thank you very much

But I'm a beginner， i still want to ask:

link up failed,DB....

what should I do ?

The JTAG1 is the reset pin?If this is the case,Our development board did not lead to the pin.

But my colleague has link up sucess,use the same hardware.But he had other problems.

Re: IMX PCIe port link down

wallyyeh — Thu, 07 Apr 2016 07:31:21 GMT

Hi, 明时:

I just copy the name from mail, sorry. :smileygrin:

You mention you're using development board, so could you also provide some information about your pcie device, board model and SDK version? for example, I use freescale's development borad - "SabreSD", and using SDK3.0.35_4.1.0

You also mention your coworker using same code, same device but didn't met this issue. Did you two change the device and see if you got a broken board/pcie device?

In kernel/arch/arm/mach-mx6/pcie.c, "link up failed" error occur while imx_pcie_link_up() execute, you can take a look.

Wally

Re: IMX PCIe port link down

minshi — Thu, 07 Apr 2016 08:07:29 GMT

Hi,Wally:

First,very thanks for you.

Then,I use the development borad which modelled on the freescale's development borad - "SabreSD", and using SDK3.0.35_4.1.0.

We only have one development board,mycoworker is debugged a year ago.

I also read that code, but I didn't find any problem.

how can I do?

明时

Re: IMX PCIe port link down

wallyyeh — Thu, 07 Apr 2016 08:18:36 GMT

Dear 明时:

OK, if you using sabreSD, the PCIE reset pin is GPIO17(which is group 7, pin 12).

At kernel/arch/arm/mach-mx6/board-mx6q_sabresd.c, you will find the pcie reset pin's define:

#define SABRESD_PCIE_RST_B_REVB

IMX_GPIO_NR(7, 12)

Since I'm not pcie expert, my only suggestion is toggle this GPIO while u-boot, and if this trick doesn't work, you may need open a tech support request from NXP.

Wally

Re: IMX PCIe port link down

minshi — Thu, 07 Apr 2016 08:52:58 GMT

Dear Wally:

Can you give me a schematic diagram?

In schematic diagram,i can not find the GPIO17.

Best wishes。

明时

Re: IMX PCIe port link down

wallyyeh — Fri, 08 Apr 2016 01:56:39 GMT

Dear 明时:

Sorry, I don't have it either.I usually get informed by asking our HW mates or Freescale FAE.

If you can't find it on the NXP website, just ask the FAE for it.

Wally