Re: [PATCH V2 01/10] Documentation: dt-bindings: mailbox: tegra: Add binding for HSP mailbox

From: Joseph Lo <josephl@nvidia.com>
To: Stephen Warren <swarren@wwwdotorg.org>, Rob Herring <robh@kernel.org>
Cc: Sivaram Nair <sivaramn@nvidia.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Alexandre Courbot <gnurou@gmail.com>,
	<linux-tegra@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	Matthew Longnecker <MLongnecker@nvidia.com>,
	<devicetree@vger.kernel.org>,
	Jassi Brar <jassisinghbrar@gmail.com>,
	<linux-kernel@vger.kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH V2 01/10] Documentation: dt-bindings: mailbox: tegra: Add binding for HSP mailbox
Date: Tue, 19 Jul 2016 15:09:06 +0800	[thread overview]
Message-ID: <534d88b6-d08e-894b-e6e1-e610fe26149a@nvidia.com> (raw)
In-Reply-To: <578D628D.60802@wwwdotorg.org>

On 07/19/2016 07:13 AM, Stephen Warren wrote:
> On 07/11/2016 10:08 AM, Stephen Warren wrote:
>> On 07/11/2016 08:14 AM, Rob Herring wrote:
>>> On Thu, Jul 07, 2016 at 12:35:02PM -0600, Stephen Warren wrote:
>>>> On 07/07/2016 12:13 PM, Sivaram Nair wrote:
>>>>> On Tue, Jul 05, 2016 at 05:04:22PM +0800, Joseph Lo wrote:
>>>>>> Add DT binding for the Hardware Synchronization Primitives (HSP). The
>>>>>> HSP is designed for the processors to share resources and communicate
>>>>>> together. It provides a set of hardware synchronization primitives
>>>>>> for
>>>>>> interprocessor communication. So the interprocessor communication
>>>>>> (IPC)
>>>>>> protocols can use hardware synchronization primitive, when operating
>>>>>> between two processors not in an SMP relationship.
>>>>
>>>>>> diff --git a/include/dt-bindings/mailbox/tegra186-hsp.h
>>>>>> b/include/dt-bindings/mailbox/tegra186-hsp.h
>>>>
>>>>>> +#define HSP_MBOX_TYPE_DB 0x0
>>>>>> +#define HSP_MBOX_TYPE_SM 0x1
>>>>>> +#define HSP_MBOX_TYPE_SS 0x2
>>>>>> +#define HSP_MBOX_TYPE_AS 0x3
>>>>>> +
>>>>>> +#define HSP_DB_MASTER_CCPLEX 17
>>>>>> +#define HSP_DB_MASTER_BPMP 19
>>>>>> +
>>>>>> +#define HSP_MBOX_ID(type, ID) \
>>>>>> +        (HSP_MBOX_TYPE_##type << 16 | ID)
>>>>>
>>>>> It will be nicer if you avoid the macro glue magic '##' for 'type'. I
>>>>> would also suggest to use braces around 'type' and 'ID'.
>>>>
>>>> This technique been used without issue in quite a few other places
>>>> without
>>>> issue, and has the benefit of simplifying the text wherever the
>>>> macro is
>>>> used. What issue do you foresee?
>>>
>>> I'm not a fan of using the macros to begin with and less so anything
>>> more complex than a single constant value. I'd rather see 2 cells here
>>> with the first being the id and the 2nd being the type.
>>>
>>> An issue with token pasting is grepping for DB, SM, etc. in kernel tree
>>> is probably noisy. Not such a big deal here, but a major PIA when you
>>> have more complex sets of includes.
>>
>> Is that a NAK or simply a suggestion? Having a single cell makes DT
>> parsing a bit simpler, since pretty much every SW stack provides a
>> default "one-cell" of_xlate implementation, whereas >1 cell means custom
>> code for of_xlate.
>
> I didn't see a response to this. Joseph, let's just use two cells
> instead. I'm rather desperately waiting for this binding to be complete
> so I can finalize the U-Boot code that uses it, and it sounds like
> changing to two cells will get an ack faster. Can you post an updated
> version of this series today/ASAP to get things moving? Thanks.
>
Okay, will use two cells instead.