i.MX ProcessorsのトピックMX6SX RDC not accessible

MX6SX RDC not accessible

LPs — Wed, 24 Feb 2016 16:35:47 GMT

Hi all,

I'm struggling with my imx6sx.

The SoC mounted on my board is the one without PCIe and GPU.

I have problem accessing RDC register: a simple md 0x20fc000 on u-boot terminal hangs the CPU. No ither action could be taken other then reset the CPU.

Same thing on sabresd demo bopard, where is mounted SoC with PCIe and GPU is mounted.

I found a comment into kernel at /arch/arm/mach-imx/pm-imx6.c at line 719

/*
  * i.MX6SX RDC needs PCIe and eim clk to be enabled
  * if Mega/Fast off, it is better to check cpu type
  * and whether Mega/Fast is off in this suspend flow,
  * but we need to add cpu type check for 3 places which
  * will increase code size, so here we just do it
  * for all cases, as when STOP mode is entered, CCM
  * hardware will gate all clocks, so it will NOT impact
  * any function or power.
  */

What does it mean? I could not access RDC registers and all module features because of my SoC haven't got PCIe module?

If yes, how could use M4 core and mcc library without that module?

Is it a chip bug?

Re: MX6SX RDC not accessible

Yuri — Thu, 25 Feb 2016 07:42:15 GMT

Hello,

There is erratum (looks like not published yet), fixed on the rev. 1.3
ERR009572: RDC: Access to RDC registers will cause the CPU to hang

on devices with PCIe disabled

It You need more details, please create request :

1) Please open www.nxp.com

2) On the top level menu, select Support > Sales and Support (http://www.nxp.com/support/sales-and-support:SUPPORTHOME).

3) On the bottom of the page, select Hardware & Software.

4) Register with your business email to access the technical NXP online support.

5) A verification email will be sent to your account. Click the embedded link to verify your access.

6) On the NXP online support page, select Contact Support from the top menu and click “submit a new case” to start the process.

Have a great day,
Yuri

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Re: MX6SX RDC not accessible

LPs — Thu, 25 Feb 2016 08:40:33 GMT

Thank you Yuri.

I found out the doc

http://cache.nxp.com/files/microcontrollers/doc/eng_bulletin/EB832.pdf?fpsp=1&WT_TYPE=Engineering%20Bulletins&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation&fileExt=.pdf