On Mon, Jan 05, 2026 at 01:29:53PM +0100, Kevin Bube wrote:

Greg KH <gregkh@linuxfoundation.org> writes:

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On Mon, Jan 05, 2026 at 11:21:48AM +0100, Kevin Bube wrote:

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Greg KH <gregkh@linuxfoundation.org> writes:

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On Sat, Jan 03, 2026 at 09:06:29PM +0100, Kevin Bube wrote:

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Add an optional threaded IRQ handler to the generic UIO driver. This allows driver developers to keep the fast IRQ handler small and move tasks to the IRQ thread. We also update the documentation accordingly.

Kevin Bube (2): UIO: Add optional IRQ thread callback Documentation: Document threaded IRQ handler for UIO

Documentation/driver-api/uio-howto.rst | 8 ++++++++ drivers/uio/uio.c | 6 +++++- include/linux/uio_driver.h | 2 ++ 3 files changed, 15 insertions(+), 1 deletion(-)

But as no in-kernel driver now uses this, it will just be removed again :(

Please always provide real users for api changes, otherwise we can't determine if they are actually working or not.

I see. Thanks for taking a look.

How was this tested if you don't have an actual user for it? Why add it if you don't have a user for it?

We have special hardware with a FPGA that requires its own customized driver at my dayjob. While the driver is GPL, the FPGA image is not (not my decision). So it makes little sense to include the driver in mainline.

There's no reason not to include it, so why not submit it?

The patch is just a part of the whole change we make for our device. I sent it because I think it may be useful for others, too. But I understand that it is bad to add an API without knowing its users and not being able to test it. My misunderstanding was that the generic UIO driver is more of a framework to derive custom drivers.

We can't ever support out-of-tree drivers for obvious reasons, so just submit your driver and then it should be fine. thanks, greg k-h