Messages in this thread | | | Date | Mon, 24 Feb 2020 12:24:42 +0100 | From | Boris Brezillon <> | Subject | Re: [PATCH v3 0/5] Introduce i3c device userspace interface |
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On Mon, 24 Feb 2020 10:53:25 +0000 Vitor Soares <Vitor.Soares@synopsys.com> wrote:
> Hi Boris, > > From: Boris Brezillon <boris.brezillon@collabora.com> > Date: Fri, Feb 21, 2020 at 17:41:16 > > > > > > > > > > > I want to make you know that none of your previous comments was ignored > > > > > and I would like to start the discussion from this point. > > > > > > > > Sure, np. I'll probably wait for a v4 exploring the option I proposed > > > > then. > > > > > > I would like to check with you: > > > - How can we prioritize the device driver over the i3cdev driver if the > > > driver is loaded after i3cdev? Currently, this is done automatically > > > without any command, and for me, this is a requirement. > > > > No devs would be bound to the i3cdev driver by default, it would have > > to be done explicitly through a sysfs knob. Which makes me realize > > we can't use the generic bind knob since it doesn't let the subsystem > > know that it's a manual bind. I thought there was a way to distinguish > > between manual and auto-bind. > > > > > - For the ioctl command structure, there is no rule about the way I did > > > or what you proposed, both are currently used in the kernel. For me it is > > > one more structure to deal with, can you point the advantages of your > > > purpose? > > > > I don't have a strong opinion on that one, though I find it a bit > > easier to follow when the number of xfers is encoded in a separate > > struct rather than extracted from the data size passed through the cmd > > argument. > > I will change it then. Do you have any suggestion for the naming to keep > it short?
I named it i3cdev_priv_xfers in the patch I sent, but you can pick a different name if you don't like this one.
> > > > > > - Regarding the ioctl codes, I tried to use those after I2C. > > > > Why start from 0x30? It doesn't make sense to me. Just because you base > > your code on something that already exists doesn't mean you have to > > copy all of it. > > I might be wrong but last I2C command is 0x20 and I tried to let some > free space in case they need. > Also I think that make sense I2C and I3C share the same 'magic number'.
Hm, I'm not sure that's a good idea. The set of ioctls for I2C and I3C are likely to be completely different, so I'd recommend using a separate namespace (AKA ioctl magic number). Wolfram, any opinion?
> > BTW, in ioctl-numbers documentation there is no reference for code 0x07.
Indeed, looks like it's not documented.
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