When is the mipi_csis_irq_handler Function Called in IMX8MPlus for Camera Streaming?

[Olivia]

Hello,

I am working with the IMX8MPlus platform to stream a monochrome camera and have encountered the static IRQ handler function mipi_csis_irq_handler(int irq, void *dev_id). I would like to understand under which conditions this function is invoked during the camera streaming process.

Could anyone provide insights into the events or scenarios that trigger the execution of this IRQ handler function? Additionally, is there any way to log or monitor when this handler is called for debugging purposes?

Your help would be greatly appreciated.

Thank you in advance!

[Manuel_Salas]

Hello @Olivia 

I hope you are doing very well.

The mipi_csis_irq_handler(int irq, void *dev_id) function is triggered by hardware interrupts from the MIPI-CSI2 receiver (CSIS) module on the i.MX8MPlus during camera streaming.
It is invoked under the following conditions:

• Transmission errors (e.g., ECC, CRC, FIFO overrun, frame sync loss).
• Start of Frame events (MIPI_CSIS_INT_SRC_FRAME_START).
• Debug events, if debugging is enabled.

The function reads the interrupt source (MIPI_CSIS_INT_SRC) and debug source (MIPI_CSIS_DBG_INTR_SRC) registers, updates error counters, and handles frame start events.

Also, for debugging or monitoring when this handler is called, you can:

Add a dev_info(csis->dev, "...") log inside the handler to print status and dbg_status.

Best regards,

Salas.