Re: [PATCH 0/7] IB/hfi1: Remove write() and use ioctl() for user access

From: Christoph Hellwig
Date: Mon Apr 18 2016 - 09:09:18 EST


On Thu, Apr 14, 2016 at 10:45:50AM -0600, Jason Gunthorpe wrote:
> On Thu, Apr 14, 2016 at 08:41:35AM -0700, Dennis Dalessandro wrote:
> > This patch series removes the write() interface for user access in favor of an
> > ioctl() based approach. This is in response to the complaint that we had
> > different handlers for write() and writev() doing different things and expecting
> > different types of data. See:
>
> I think we should wait on applying these patches until we globally sort out
> what to do with the rdma uapi.
>
> It just doesn't make alot of sense for drivers to have their own personal
> char devices. :(

I looked through the patches I tend to disagree - while we should wait
for a global UAPI for anything that's actually RDMA/verbs related these
seem to be misc little bits specific to the driver that have no business
in any sort of generic RDMA API.

> A second char dev for the eeprom? How is that OK? Why aren't you using
> the I2C layer for this?

... but this is a really good question, although the right layer to
plug this in would be the eeprom code in drivers/nvmem/