Mity CPU Platforms » MityDSP-L138 (ARM9 Based Platforms)

09/12/2023

JC 08:36 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jonathan,
Excellent, thanks for the steadfast effort on this!
Interesting regarding the DONE LED. We are not certain why it slowly lights either, as we observe it being strongly driven HIGH once the boot finishes. The POWER GOOD L... Jon Cox

JC 08:24 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jon Cox wrote in message#6483:
> Jonathan,
> ...
Okay will do. I was told someone would have time next week to look it over and merge it in.
>
> ...
Note the DONE led is driven by the fpga after it is programmed and is an open drai... Jonathan Cormier

JC 07:54 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jonathan,
We have tested the compiled branch and it seems to be working as intended. We have not noticed any I2C hangs yet after 100 boot cycles, so I think it is safe to say the kernel changes are at least as stable as the live one. ... Jon Cox

09/11/2023

JC 05:52 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jonathan,
Fantastic! This is exactly what we were looking to implement, and the fact that it is automatic as-is is even better. We've compiled the kernel and will test it on our systems today/tomorrow and let you know whether it works... Jon Cox

JC 05:42 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Let me know if it works and i'll merge the commits into the main 3.2 branch Jonathan Cormier

JC 05:37 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Its supposed to catch a bus hang and switch into bus recovery by itself.
I'd suggest going into drivers/i2c/i2c-core.c and changing dev_dbg to dev_err so you can see when the kernel tries to do these recoveries in dmesg. Jonathan Cormier

JC 05:32 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jonathan,
Excellent - thanks for the very quick and thorough fix on this.
Regarding the usage of these committed changes, will we have to invoke function calls to resolve the bus hang or should this potentially catch and fix any po... Jon Cox

JC 04:15 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Hi Jon,
Can you try out the commits pushed to this branch and let me know if it works? I don't have time right now to try it out but it builds.
https://support.criticallink.com/gitweb/?p=linux-davinci.git;a=shortlog;h=refs/heads/mit... Jonathan Cormier

09/08/2023

JC 10:36 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jonathan,
Thank you for the very quick and thorough response. We have found the i2c-davinci driver in our MDK / board support package ARM/linux/linux-davinci/drivers/i2c/busses/i2c-davinci.c.
We are using the 3.2 kernel. Based on ... Jon Cox

JC 06:39 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Note as is, the bus recovery I linked looks like it requires i2c gpio pins which probably won't work for the L138. In the newer kernel version they have a way to put the i2c module into a manual mode which doesn't require separate gpio ... Jonathan Cormier

JC 06:19 PM PCB Development: RE: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Jon Cox wrote:
> Hello,
> ...
This is almost certainly an i2c slave holding SDA low. I know on a separate project, I've seen particular issues with i2c slaves that use 16-bit addresses, but really any i2c slave could misbehave and hol... Jonathan Cormier

JC 05:38 PM PCB Development: MityDSP-L138F Boot issue, I2C0 (PCB Dev Post)

Hello,
We are developing on the MityDSP-L138F platform and have noticed an intermittent issue with the I2C bus hanging due to SDA being held LOW. We are uncertain whether it is a slave or the OMAP I2C Module pulling SDA low.
We are... Jon Cox

JC 06:40 PM Software Development: RE: MityDSP-L138F I2C bus hang (SDA held low)

Saw the other post first so responded there. https://support.criticallink.com/redmine/boards/11/topics/6473?r=6475 Jonathan Cormier

JC 05:38 PM Software Development: MityDSP-L138F I2C bus hang (SDA held low)

Hello,
We are developing on the MityDSP-L138F platform and have noticed an intermittent issue with the I2C bus hanging due to SDA being held LOW. We are uncertain whether it is a slave or the OMAP I2C Module pulling SDA low.
We are... Jon Cox

08/31/2023

MW 12:16 AM PCB Development: RE: MityDSP-L138F Boot issue, I2C0

Hi JC,
The low level boot software (first stage, user boot loader, UBL) reads the EEPROM on the I2C0 bus to determine the model number, which includes information needed for initializing the DDR (e.g., the size of the DDR is needed, e... Michael Williamson

08/30/2023

JC 10:16 PM PCB Development: MityDSP-L138F Boot issue, I2C0

I'm an electrical engineer working on the design of a system using the MityDSP SoM - in particular, the L138-FI-325-RC.
We are noticing an issue with the device booting properly only on some of our carrier boards - we have high confid... Jon Cox