Re: [PATCH v6 1/2] fpga: dfl: add the userspace I/O device support for DFL devices

From: Greg KH
Date: Sun Jan 17 2021 - 10:46:17 EST


On Wed, Jan 13, 2021 at 09:54:07AM +0800, Xu Yilun wrote:
> This patch supports the DFL drivers be written in userspace. This is
> realized by exposing the userspace I/O device interfaces.
>
> The driver leverages the uio_pdrv_genirq, it adds the uio_pdrv_genirq
> platform device with the DFL device's resources, and let the generic UIO
> platform device driver provide support to userspace access to kernel
> interrupts and memory locations.

Why doesn't the existing uio driver work for this, why do you need a new
one?

> ---
> drivers/fpga/Kconfig | 10 +++++
> drivers/fpga/Makefile | 1 +
> drivers/fpga/dfl-uio-pdev.c | 93 +++++++++++++++++++++++++++++++++++++++++++++

uio drivers traditionally go in drivers/uio/ and start with "uio", so
shouldn't this be drivers/uio/uio_dfl_pdev.c to match the same naming
scheme?

But again, you need to explain in detail, why the existing uio driver
doesn't work properly, or why you can't just add a few lines to an
existing one.

thanks,

greg k-h