Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 17 Feb 2020 18:37:47 +0100
From:   Boris Brezillon <boris.brezillon@collabora.com>
To:     Vitor Soares <Vitor.Soares@synopsys.com>
Cc:     Jose.Abreu@synopsys.com, Joao.Pinto@synopsys.com, arnd@arndb.de,
        wsa@the-dreams.de, gregkh@linuxfoundation.org,
        bbrezillon@kernel.org, linux-kernel@vger.kernel.org,
        broonie@kernel.org, linux-i3c@lists.infradead.org
Subject: Re: [RFC v2 0/4] Introduce i3c device userspace interface
Message-ID: <20200217183747.6a18d6c4@collabora.com>
In-Reply-To: <20200217155141.08e87b3f@collabora.com>
References: <cover.1580299067.git.vitor.soares@synopsys.com>
        <20200217155141.08e87b3f@collabora.com>
Organization: Collabora
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 17 Feb 2020 15:51:41 +0100
Boris Brezillon <boris.brezillon@collabora.com> wrote:

> Hello Vitor,
> 
> Sorry for taking so long to reply, and thanks for working on that topic.
> 
> On Wed, 29 Jan 2020 13:17:31 +0100
> Vitor Soares <Vitor.Soares@synopsys.com> wrote:
> 
> > For today there is no way to use i3c devices from user space and
> > the introduction of such API will help developers during the i3c device
> > or i3c host controllers development.
> > 
> > The i3cdev module is highly based on i2c-dev and yet I tried to address
> > the concerns raised in [1].
> > 
> > NOTES:
> > - The i3cdev dynamically request an unused major number.
> > 
> > - The i3c devices are dynamically exposed/removed from dev/ folder based
> >   on if they have a device driver bound to it.  
> 
> May I ask why you need to automatically bind devices to the i3cdev
> driver when they don't have a driver matching the device id
> loaded/compiled-in? If we get the i3c subsystem to generate proper
> uevents we should be able to load the i3cdev module and bind the device
> to this driver using a udev rule.

Hm, looks like we already send a proper MODALIAS [1], so we can actually
implement this auto-bind to i3cdev in udev (fall back on i3cdev
load+bind if no matching module is found).

[1]https://elixir.bootlin.com/linux/latest/source/drivers/i3c/master.c#L269