On Fri, Jan 21, 2022 at 09:03:43AM +0000, Markus Mirevik wrote:
I have a problem with a custom bord based on SoC am335x and a driver
utilizing a GPIO line for interrupts.
I have two mcp2518fd chip connected on one SPI line and everything
works, but it's hogs a lot of CPU.
In the current setup only one chip is connected and it only receives packets.
The mcp2518fd is connected with 2 interrupt lines one "main" and one for
rx frames.
The problem is that for every frame received the interrupt handler is run
twice, which is kind of expensive since it's a SPI call to the chip to check
interrupt registers.
To me it looks like the interrupt is fired again as soon as it's unmasked.
Either because it's queued? or maybe not cleared internally?
I have scoped the interrupt signal and its real good without any glitches.
I'm currently running a yocto build:
Linux botekcc 5.10.79-yocto-tiny #1 SMP Tue Nov 16 03:57:43 UTC 2021
armv7l armv7l armv7l GNU/Linux
But the mcp251xfd driver is from net-next/master
mcp251xfd_irq is the irqhandler for the mcp2518fd and is added like this:
err = request_threaded_irq(spi->irq, NULL, mcp251xfd_irq,
IRQF_SHARED | IRQF_ONESHOT,
dev_name(&spi->dev), priv);
You haven't set a IRQF_TRIGGER flag, so you are getting the "as-already-
configured" behaviour, which on your setup is both edges?
Try adding IRQF_TRIGGER_RISING, IRQF_TRIGGER_FALLING,
IRQF_TRIGGER_HIGH or IRQF_TRIGGER_LOW, as appropriate to your use
case, to your flags.
Cheers,
Kent.
