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Subject: Re: [PATCH v7 16/20] arm64: tegra: Enable wake from deep sleep on RTC
 alarm
To:     Sowjanya Komatineni <skomatineni@nvidia.com>,
        thierry.reding@gmail.com, jonathanh@nvidia.com, tglx@linutronix.de,
        jason@lakedaemon.net, marc.zyngier@arm.com,
        linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com
Cc:     pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org,
        linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org,
        jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org,
        devicetree@vger.kernel.org
References: <1564532424-10449-1-git-send-email-skomatineni@nvidia.com>
 <1564532424-10449-17-git-send-email-skomatineni@nvidia.com>
 <1233ad49-22eb-a90a-d7cf-5fe133ded177@gmail.com>
 <d4709085-f705-2608-08a8-65b238ae8844@nvidia.com>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <4f8b9ee7-5402-6463-d6d2-7b00e274a185@gmail.com>
Date:   Thu, 1 Aug 2019 13:43:15 +0300
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01.08.2019 0:08, Sowjanya Komatineni пишет:
> 
> On 7/31/19 4:04 AM, Dmitry Osipenko wrote:
>> 31.07.2019 3:20, Sowjanya Komatineni пишет:
>>> This patch updates device tree for RTC and PMC to allow system wake
>>> from deep sleep on RTC alarm.
>>>
>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>> ---
>>>   arch/arm64/boot/dts/nvidia/tegra210.dtsi | 5 ++++-
>>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/nvidia/tegra210.dtsi
>>> b/arch/arm64/boot/dts/nvidia/tegra210.dtsi
>>> index 659753118e96..30a7c48385a2 100644
>>> --- a/arch/arm64/boot/dts/nvidia/tegra210.dtsi
>>> +++ b/arch/arm64/boot/dts/nvidia/tegra210.dtsi
>>> @@ -768,7 +768,8 @@
>>>       rtc@7000e000 {
>>>           compatible = "nvidia,tegra210-rtc", "nvidia,tegra20-rtc";
>>>           reg = <0x0 0x7000e000 0x0 0x100>;
>>> -        interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>;
>>> +        interrupts = <16 IRQ_TYPE_LEVEL_HIGH>;
>>> +        interrupt-parent = <&pmc>;
>>>           clocks = <&tegra_car TEGRA210_CLK_RTC>;
>>>           clock-names = "rtc";
>>>       };
>>> @@ -778,6 +779,8 @@
>>>           reg = <0x0 0x7000e400 0x0 0x400>;
>>>           clocks = <&tegra_car TEGRA210_CLK_PCLK>, <&clk32k_in>;
>>>           clock-names = "pclk", "clk32k_in";
>>> +        #interrupt-cells = <2>;
>>> +        interrupt-controller;
>>>             powergates {
>>>               pd_audio: aud {
>>>
>> Is this a backwards-compatible change? Or it's not really worth to care
>> about the compatibility with older kernel versions, I'm not sure about
>> overall state of T210 in the upstream kernel.
> I don't think its required to be backwards-compatible as SC7 entry/exit
> implementation for T210 is with this patch series onwards..

The new device tree binary should work with older kernel versions, AFAIK
this is the upstream rule. But if kernel support isn't in a very good
shape and not much people are using it, then obviously it is not very
important.