Why do I see the "timeout occurred, waiting for async message, trying for polling" message in Agilex™ 7 FPGA devices when reading data from the Linux* Hardware Monitor?

Description

Due to the absence of the interrupt configuration in the SVC driver node in the Agilex™ 7 FPGA Linux* device tree in Quartus® Prime versions 24.3.1 and 25.1, you may observe the following message in the Linux serial console when reading data from the hardware monitor or any other driver that depends on the SVC driver:

 [200.458962] hwmon hwmon0: timeout occurred, waiting for async message, trying for polling

 

The missing interrupt configuration is needed after the implementation on the Quartus® Prime 24.3.1 release of a new mechanism based on interrupts on the SVC handler to receive data from the SDM. Because of this, the message displayed is an indication that there was a timeout to receive the interrupt to notify data response ready, so it will proceed with the alternate polling mechanism. The timeout introduces an undesired delay to get the response.

Resolution

To workaround this problem, you need to add the interrupt configuration in the SVC driver node:

 

               firmware {

                  svc {

                         compatible = "intel,agilex-svc";

                         method = "smc";

                         memory-region = <&service_reserved>;

                         interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>;

                         interrupt-parent = <&intc>;

                         :

 

The problem will be fixed in a future release of the Quartus® Prime Pro Edition Software.