AM4378: About the register setting of UART_SYSC

Hi Nishigata-san,

I will look into this and get back to you in a few days.

Hi,

I would like to know how things are going about the issue.

Best Regards,

Kouji Nishigata

Okay, now I see where the confusion is:
TRM Table 21-71 shows bit0 value 1 is reserved.

Let me check internally to confirm if the TRM is accurately then we likely need to update the kernel driver to not set bit0.

Hi, Bin Liu

Do you have any new information on this matter?
I don't think the customer will change anything about the UART_SYSC Bit, but I'm not sure.
In case there is a change in the kernel driver, they will need to update or patch it.

Best Regards,

Kouji Nishigata

Hi Nishigata-san,

I am still waiting for response from our hardware team to confirm the TRM information showing that bit0 value 1 is reserved.

If it is not reserved, the kernel driver is correct and the TRM needs to be updated;

If it is indeed reserved, the kernel should be patched to not set the register bit. We will provide the patch.

Hi, Bin Liu

Thanks for your response.

Is it likely that a patch will be issued to fix this issue? And when will that be?

Best Regards,

Kouji Nishigata

Hi NIshigata-san,

The issue will be fixed in the next AM437x Processor SDK v9.1, which is scheduled by end of October.

However, if you want this issue to be fixed in SDKv7.3, you can follow my instruction above to modify the kernel device tree code in SDK v7.3.

Hi, Bin Liu

Thanks for your response.

I was inadvertently referring to the issue of a ticket, so you meant the fix for the next update.
Since you want to do the fix for SDK7.3, that fix is not good enough.
Does the customer need to find and do the fix to 7.3 themselves?
(Will you be providing some sort of patch to the code?)

Best Regards,

Kouji Nishigata

Hi Nishigata-san,

user1201164 said:

Does the customer need to find and do the fix to 7.3 themselves?

It is trivial to create the patch based on my instruction below. Please let me know if your customer doesn't understand the instruction or fail to create the patch.

Remove the "SYSC_OMAP2_AUTOIDLE" flag from device tree property "ti,sysc-mask" in the "target-module" nodes corresponding to all UART nodes in kernel device tree am437x-l4.dtsi.

Hi, Bin Liu

Thanks for your response.

I will contact the customer and ask if it can be changed.
I will try to contact you if there is any problem.

Best Regards,

Kouji Nishigata