HPET Timer 2, IRQ11 interrupt triggered every 20us, Baytrail E3815

[JCofr2]

Hi. I was redirected from the community forums and I desperately need advice.

I am trying to use IRQ11 for HPET and I have programmed the HPET Timer 2 comparator register to 500ms. Whenever I enable IRQ11, I get a trigger every 20us instead.

Main problem is I did not yet enable the HPET, only the IRQ11 interrupt in PIC and this happens. No matter what value I put in comparator 2, it is always 20us.

I have a hunch that since HPET shares IRQ11, this might be cause by either SERIRQ, PIRQx, or SCI.

My board is a Kontron using E3815, running under VxWorks but I am also looking at the UEFI BIOS programming side.

I am debugging now in the UEFI Shell, and assuming I have the EDK2 Workspace, which part of the UEFI programming determines the use of IRQ11?

I have attached a snapshot of my ISR using GPIO and that is where I got the measurement response of IRQ11.

I am completely at loss right now and until I hear something from Kontron support, I need to figure out the cause of this issue from UEFI perspective. Is it also doable to create an ISR in UEFI so I can replicate the problem?

Can anyone give me some direction?

Many thanks,

Josh

[CarlosAM_INTEL]

Hello, Josh0031 :

Thank you for contacting Intel Embedded Community.

We would like to help you with your consultations related to this third party design but its information is available from its manufacturer.

In order to contact them as a reference, please feel free to fill out the form stated at the following website:

https://www.kontron.com/about-kontron/company-overview/contact-us/forms/contact-support https://www.kontron.com/about-kontron/company-overview/contact-us/forms/contact-support

They will be more than glad to assist you.

We hope that this information may help you.

Best regards,

Carlos_A.

[JCofr2]

Hi Carlos A.,

Good day. I am working to find a solution to this as I have yet to hear on the Kontron side. I am on a tight deadline and that is why I resorted to the embedded community for inputs.

HPET is not new technology and it is common to all Intel platforms. That is why I need very much help in which part of UEFI might be responsible for assigning IRQ11.

I am looking at EDKII for any instance of HPET and IRQ11 but it would be of great help if someone would point me to the right direction.

My objective is to find which part of the UEFI code is also controlling IRQ11 (SERIRQ, SCI, or PIRQx) and replicating the issue on UEFI Shell will greatly help me.

With best regards,

Josh

[CarlosAM_INTEL]

Hello, Josh0031:

Thanks for your update.

We suggest you review with the assistance of the BIOS developer of the third party design related to this consultation the information stated in Tabel 28-8, on page 143 of thehttps://edc.intel.com/Link.aspx?id=7010 Intel(R) Atom(TM) processor E3800-M/D SoC: BIOS Writer's Guide (Volume 2 of 2) document number 514147, and in section 3.3, on pages 20, 21, and 22 of the https://edc.intel.com/Link.aspx?id=7011 Intel(R) Atom(TM) SoC E3800-I: BIOS Writer's Guide Addendum document # 526998.

These documents are available when you have an Embedded Design Center (EDC) Privileged account. In order to request a Privileged EDC account, go to https://www-ssl.intel.com/content/www/us/en/forms/intelligent-systems/registration-po1.html Accounthttps://www-ssl.intel.com/content/www/us/en/forms/intelligent-systems/registration-po1.html and filling out the form.

In order to help you with this process, we suggest you use a business email address to evade any inconvenience. Please avoid the free email provider's address (such the provided by Hotmail, Gmail, yahoo, or others).

We hope that this information may help you.

Best regards,

Carlos_A.