Activity
From 03/29/2016 to 04/27/2016
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... - 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
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.
- 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 ...
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
- 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...
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
- 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]]
04/13/2016
- 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... - 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... - 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... - 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.
>
> ...
... - MF 09:48 AM Software Development: RE: High latency for DMTimer interrupt
- This code:
- 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?
- 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...
04/12/2016
- GG 02:25 PM Software Development: RE: High latency for DMTimer interrupt
- Hi Mary,
You mentioned that your maximum latency is ~500 usec. Is this maximum a rare or common occurrence? What is your average latency?
One utility that might be helpful in figuring out what is going on is ftrace (https://www.k... - I have implemented a timer interrupt in a kernel module. At the start of the isr, it reads the timer value which should be close to the load register value. I am measuring the latency as the difference between the auto-reload value and ...
04/08/2016
- JC 04:24 PM Software Development: RE: Building an SD Card
- Tom Tatakis wrote:
> This is a custom board- I did move the init of mmc back to the early init stage as a test and the file system came up and booted successfully. So that was indeed the issue.
Okay thats good.
> ...
Looks like yo... - JC 04:21 PM Software Development: RE: Building an SD Card
- Tom,
We are working on a yocto filesystem release which allows you to build a new yocto based filesystem from source. Would you be interested in this? - TT 03:52 PM Software Development: RE: Building an SD Card
- Actually I do have a question- do you have a pointer to documentation that tells me how to build an SD card image from scratch? I went looking for this at the beginning of this process and could not find anything.
Thanks again.
- TT 03:50 PM Software Development: RE: Building an SD Card
- This is a custom board- I did move the init of mmc back to the early init stage as a test and the file system came up and booted successfully. So that was indeed the issue. Now I have another problem I need to solve. Our goal is to h...
- BD 02:08 PM Software Development: RE: Building an SD Card
- Tom, one more question: are you running this on a Critical Link Development Board or your own custom baseboard?
04/07/2016
- JC 09:57 AM Software Development: RE: Building an SD Card
- Looking at the logs here are a few things I see.
* On the sd card boots, you are still loading u-boot from the nand. This is okay as long as you know its happening and aren't lost when you try to update the u-boot on the sd card and ... - TT 09:02 AM Software Development: RE: Building an SD Card
- Thanks for the reply- of course now the symptoms have changed. The bad boot now stops waiting for the file system partition. Although at least this gives me something to work with and track down I've attached the 3 logs in case you see...
04/06/2016
- JC 02:36 PM Software Development: RE: Building an SD Card
- Actually 3 logs. The two sd card boot logs and the nand boot log with the new kernel.
- JC 02:34 PM Software Development: RE: Building an SD Card
- Tom,
Could you include the full boot log of the working and the broken boots? - Hello- First, I have a working SD card that boots that I have been using for over a year. I also have a newer kernel that I have built that runs when I burn it into the NAND. I want to upgrade the SD card to use this new uImage. I cop...