Mity CPU Platforms » MitySOM-335x (ARM Cortex-A8 Based Products)

05/03/2016

JC 08:54 AM Software Development: RE: iproute2 for SocketCAN with 3.2 Kernel

Okay, would you mind creating a forum post over there as it may help people find it in the future who are looking for a similar issue? Jonathan Cormier

EL 04:04 AM Software Development: RE: iproute2 for SocketCAN with 3.2 Kernel

Thanks for the quick response.
I'm afraid I posted this in the wrong topic yesterday, I am using an Industrial IO board with an omap L138 arm 9, not a cortex A8.
I am referring to this wiki page https://support.criticallink.com/... edward lambert

05/02/2016

JC 10:58 AM Software Development: RE: iproute2 for SocketCAN with 3.2 Kernel

Added a 335x specific CAN wiki page: [[Using_CAN_port]] Jonathan Cormier

JC 10:44 AM Software Development: RE: iproute2 for SocketCAN with 3.2 Kernel

There should be no need to install any packages. I've attached our cantest script. It expects can0 to be connected to can1. Jonathan Cormier

JC 10:38 AM Software Development: RE: iproute2 for SocketCAN with 3.2 Kernel

Which wiki page are you referencing? Jonathan Cormier

EL 10:35 AM Software Development: iproute2 for SocketCAN with 3.2 Kernel

The iproute2 utility for linux 3.2 seems to be unavailable from opkg. I am therefore unable to run the example in the wiki, which I was hoping to use to prove the CAN interface. Is there another way to access the CAN interface or to acqu... edward lambert

04/25/2016

JC 03:42 PM Software Development: RE: All devices on i2c on the AM335 SOM

The factory config definition can be found here:
http://support.criticallink.com/gitweb/?p=linux-mityarm-335x.git;a=blob;f=arch/arm/mach-omap2/mityarm335x.h;h=5b75f982a46a56056ce71cc0aab38ccb09ee2a28;hb=HEAD
Note: Although we provide... Jonathan Cormier

JO 03:33 PM Software Development: RE: All devices on i2c on the AM335 SOM

Is there any way I can read the factory config eeprom and use that data to verify the correct SOMs are installed or use the data to compare mac address for example?
-Joe Joseph Orender

04/20/2016

JC 01:48 PM Software Development: RE: High latency for DMTimer interrupt

Mary, Thank you for this detailed post. Please let us know how this works out. Jonathan Cormier

MF 01:44 PM Software Development: RE: High latency for DMTimer interrupt

Here's what I did to apply the RT PREEMPT patch:
Helpful websites:
https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO
https://www.osadl.org/Single-View.111+M5d103f5bd04.0.html
Get the patch (get the latest patch that _matches ... Mary Frantz

04/15/2016

JC 10:06 AM Software Development: RE: High latency for DMTimer interrupt

Note that the RT linux page also has an Ftrace guide: https://rt.wiki.kernel.org/index.php/Ftrace Jonathan Cormier

GG 09:53 AM Software Development: RE: High latency for DMTimer interrupt

Hi Mary,
Regarding RT Linux I would specifically recommend https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO as a primer for understanding what the RT kernel changes from mainline as well as how to apply the patch. Note that this... Gregory Gluszek

04/14/2016

BD 11:43 PM Software Development: RE: High latency for DMTimer interrupt

Mary,
Here is a link to the RT Linux Wiki:
https://rt.wiki.kernel.org/index.php/Main_Page
There's a direct link to the 3.2-rt patch readme: https://www.kernel.org/pub/linux/kernel/projects/rt/3.2/README
-Bob
Bob Duke

JC 03:35 PM Software Development: RE: All devices on i2c on the AM335 SOM

I created a wiki page for this information. Let me know if it answers your question.
[[MitySOM-335x_I2C_Addresses]] Jonathan Cormier

04/13/2016

JO 02:30 PM Software Development: All devices on i2c on the AM335 SOM

Hello,
I am writing some diagnostic software for our device to run through and make sure everything seems to be present and working on the carrier board. Is there a document on the wiki somewhere that details all the devices on the i2... Joseph Orender

JC 11:09 AM Software Development: RE: High latency for DMTimer interrupt

Mary Frantz wrote:
> For more information about how the DM Timer works, refer the the AM335x Technical Reference Manual.
> ...
Okay thanks. I haven't used the hardware timers before.
>
> ...
Heres what I get when I boot the devkit f... Jonathan Cormier

MF 10:59 AM Software Development: RE: High latency for DMTimer interrupt

For more information about how the DM Timer works, refer the the AM335x Technical Reference Manual.
To summarize, the DMTimer is configured to auto-reload the value in the reload register (in this case, 0xFFFFD120.) when it reaches it... Mary Frantz

JC 10:09 AM Software Development: RE: High latency for DMTimer interrupt

Mary Frantz wrote:
> This code:
> ...
What is the relation between the reload value and the start values?
I know that print statements inside interrupts are very frowned on, could they be causing the high latency values.
>
> ...
... Jonathan Cormier

MF 09:48 AM Software Development: RE: High latency for DMTimer interrupt

This code: Mary Frantz

JC 09:28 AM Software Development: RE: High latency for DMTimer interrupt

Mary Frantz wrote:
> I see this when the printk() call displays the last 16 'start' counter values.
What do you mean by this? You see the low latency or the high latency when it prints?
Jonathan Cormier

MF 08:58 AM Software Development: RE: High latency for DMTimer interrupt

No, this high latency is rare. Typical is more like 3 usec. I see this when the printk() call displays the last 16 'start' counter values.
Note, I have also removed the lcdc and touchscreen support from the kernel to eliminate those... Mary Frantz