From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michal Simek <michal.simek@xilinx.com>
Subject: Re: [PATCH v11 03/11] firmware: xilinx: Add zynqmp IOCTL API for
 device control
Date: Mon, 10 Sep 2018 14:35:04 +0200
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To: Moritz Fischer <moritz.fischer@ettus.com>, Olof Johansson <olof@lixom.net>
Cc: Jolly Shah <jolly.shah@xilinx.com>, "ard.biesheuvel@linaro.org" <ard.biesheuvel@linaro.org>, Ingo Molnar <mingo@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, matt@codeblueprint.co.uk, Sudeep Holla <sudeep.holla@arm.com>, hkallweit1@gmail.com, Kees Cook <keescook@chromium.org>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@codeaurora.org>, Michal Simek <michal.simek@xilinx.com>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, linux-clk <linux-clk@vger.kernel.org>, rajanv@xilinx.com, Linux ARM Mailing List <linux-arm-kernel@lists.infradead.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, DTML <devicetree@vger.kernel.org>, Jolly Shah <jollys@xilin>
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On 9.9.2018 21:20, Moritz Fischer wrote:
> Hi Olof,
> 
> On Sat, Sep 8, 2018 at 6:18 PM, Olof Johansson <olof@lixom.net> wrote:
>> Hi,
>>
>> On Fri, Aug 3, 2018 at 10:53 AM, Jolly Shah <jolly.shah@xilinx.com> wrote:
>>> From: Rajan Vaja <rajanv@xilinx.com>
>>>
>>> Add ZynqMP firmware IOCTL API to control and configure
>>> devices like PLLs, SD, Gem, etc.
>>>
>>> Signed-off-by: Rajan Vaja <rajanv@xilinx.com>
>>> Signed-off-by: Jolly Shah <jollys@xilinx.com>
>>
>> This patch worries me somewhat. It's a transparent pass-through ioctl
>> driver. Is there a spec available for what the implemented IOCTLs are?
>>
>> Should some of them be proper drivers instead of an opaque
>> pass-through like this? Could some of them have stability impact on
>> the platform such that there are security concerns and the list of
>> arguments should somehow be sanitized?
> 
> I tend to agree with this, good catch.
> 
>> What's the intended usecase anyway? Just a debug tool during
>> development, or something that you expect heavy use of by some
>> userspace middleware?
> 
> I suspect it is another attempt to make userspace clocks/plls work? Scary.

none is trying to do that as far as I know.

Thanks,
Michal