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Date:   Mon, 7 Aug 2023 11:57:04 +0200
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Subject: Re: [PATCH] tty: serial: samsung: Set missing PM ops for hibernation
 support
Content-Language: en-GB, sv-SE
To:     Andi Shyti <andi.shyti@kernel.org>
CC:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-samsung-soc@vger.kernel.org>,
        <linux-serial@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <kernel@axis.com>
References: <20230803-samsung_tty_pm_ops-v1-1-1ea7be72194d@axis.com>
 <20230805213824.ol7sr3b52rwrsfs6@intel.intel>
From:   Anton Eliasson <anton.eliasson@axis.com>
In-Reply-To: <20230805213824.ol7sr3b52rwrsfs6@intel.intel>
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On 05/08/2023 23.38, Andi Shyti wrote:
> Hi Anton,
>
> On Thu, Aug 03, 2023 at 01:26:42PM +0200, Anton Eliasson wrote:
>> At least freeze, restore and thaw need to be set in order for the driver
>> to support system hibernation. The existing suspend/resume functions can
>> be reused since those functions don't touch the device's power state or
>> wakeup capability. Use the helper macros SET_SYSTEM_SLEEP_PM_OPS and
>> SET_NOIRQ_SYSTEM_SLEEP_PM_OPS for symmetry with similar drivers.
> and why do we need hibernation in this device?
>
> Andi

Hi!

I wanted to test whether hibernation is possible on our SoC, even though 
it is not a common feature on embedded ARM systems. This is the only 
mainline driver that I found that needed modification, for my 
proof-of-concept anyway, and I couldn't see any harm in the change.


Anton Eliasson