Re: [PATCH 3/6] ARM: dts: broadcom: Fix SP804 node

From: "André Przywara" <andre.przywara@arm.com>
To: Florian Fainelli <f.fainelli@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	devicetree@vger.kernel.org
Cc: Scott Branden <sbranden@broadcom.com>,
	Ray Jui <rjui@broadcom.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	linux-kernel@vger.kernel.org,
	bcm-kernel-feedback-list@broadcom.com,
	Haojian Zhuang <haojian.zhuang@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 3/6] ARM: dts: broadcom: Fix SP804 node
Date: Fri, 28 Aug 2020 14:59:52 +0100	[thread overview]
Message-ID: <60929faf-fdcf-a434-1acb-c77f92818955@arm.com> (raw)
In-Reply-To: <ecb277f9-1328-c64c-dd42-7a346ba61f8e@gmail.com>

On 26/08/2020 21:55, Florian Fainelli wrote:
> On 8/26/20 11:59 AM, Florian Fainelli wrote:
>> On 8/26/20 11:53 AM, André Przywara wrote:
>>> On 26/08/2020 19:42, Florian Fainelli wrote:

Hi Florian,

>>>
>>> Hi,
>>>
>>>> On 8/26/20 11:38 AM, Andre Przywara wrote:
>>>>> The DT binding for SP804 requires to have an "arm,primecell" compatible
>>>>> string.
>>>>> Add this string so that the Linux primecell bus driver picks the device
>>>>> up and activates the clock.
>>>>>
>>>>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>>>>
>>>> The commit subject should be:
>>>>
>>>> ARM: dts: NSP: Fix SP804 compatible node
>>>>
>>>> and we should probably have a Fixes tag that is:
>>>>
>>>> Fixes: a0efb0d28b77 ("ARM: dts: NSP: Add SP804 Support to DT")
>>>>
>>>> Could you please re-submit with those things corrected? Thanks
>>>
>>> Sure, will include that in a v2.
>>>
>>> Out of curiosity, do you have the hardware and can check the impact that
>>> has?
>>
>> I have the hardware and could run some tests if you would like.
>>
>>> Not sure we actually create the device without the primecell compatible?
>>> Or is the sp804 an exception here, compared to the other AMBA devices
>>> (SP805, PL011)?
>>
>> No idea, I have never used those timers personally, and I doubt that
>> anybody besides me within broadcom and hobbyists actually care about NSP
>> these days.
> 
> Seems to be working fine for me with your patch applied, it probes:
> 
> # dmesg | grep sp804
> [    0.035363] clocksource: arm,sp804: mask: 0xffffffff max_cycles:
> 0xffffffff, max_idle_ns: 15290083572 ns
> 
> and it is usable:
> 
> # cat clocksource0/available_clocksource
> arm_global_timer arm,sp804
> 
> and appears to work:
> 
> # echo "arm,sp804" > clocksource0/current_clocksource
> [  105.108547] clocksource: Switched to clocksource arm,sp804
> 
> # date; sleep 5; date
> Thu Jan  1 00:01:51 UTC 1970
> Thu Jan  1 00:01:56 UTC 1970
> 
> Feel free to add Tested-by: Florian Fainelli <f.fainelli@gmail.com> in
> your v2, thanks André!

Wow, thanks a lot for this test!

Sending out a v2 in a minute.

Cheers,
Andre

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