Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Received-SPF: TempError (protection.outlook.com: error in processing during
 lookup of xilinx.com: DNS Timeout)
Subject: Re: [PATCH v2] drivers: soc: xilinx: Call InitFinalize from
 late_initcall_sync instead of probe
To:     Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com>,
        ard.biesheuvel@linaro.org, mingo@kernel.org,
        gregkh@linuxfoundation.org, matt@codeblueprint.co.uk,
        sudeep.holla@arm.com, hkallweit1@gmail.com, keescook@chromium.org,
        dmitry.torokhov@gmail.com, michal.simek@xilinx.com,
        Arnd Bergmann <arnd@arndb.de>
Cc:     rajanv@xilinx.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, tejasp@xilinx.com, jollys@xilinx.com,
        Rajan Vaja <rajan.vaja@xilinx.com>
References: <1599693000-25641-1-git-send-email-amit.sunil.dhamne@xilinx.com>
From:   Michal Simek <michal.simek@xilinx.com>
Autocrypt: addr=michals@xilinx.com; keydata=
 xsFNBFFuvDEBEAC9Amu3nk79+J+4xBOuM5XmDmljuukOc6mKB5bBYOa4SrWJZTjeGRf52VMc
 howHe8Y9nSbG92obZMqsdt+d/hmRu3fgwRYiiU97YJjUkCN5paHXyBb+3IdrLNGt8I7C9RMy
 svSoH4WcApYNqvB3rcMtJIna+HUhx8xOk+XCfyKJDnrSuKgx0Svj446qgM5fe7RyFOlGX/wF
 Ae63Hs0RkFo3I/+hLLJP6kwPnOEo3lkvzm3FMMy0D9VxT9e6Y3afe1UTQuhkg8PbABxhowzj
 SEnl0ICoqpBqqROV/w1fOlPrm4WSNlZJunYV4gTEustZf8j9FWncn3QzRhnQOSuzTPFbsbH5
 WVxwDvgHLRTmBuMw1sqvCc7CofjsD1XM9bP3HOBwCxKaTyOxbPJh3D4AdD1u+cF/lj9Fj255
 Es9aATHPvoDQmOzyyRNTQzupN8UtZ+/tB4mhgxWzorpbdItaSXWgdDPDtssJIC+d5+hskys8
 B3jbv86lyM+4jh2URpnL1gqOPwnaf1zm/7sqoN3r64cml94q68jfY4lNTwjA/SnaS1DE9XXa
 XQlkhHgjSLyRjjsMsz+2A4otRLrBbumEUtSMlPfhTi8xUsj9ZfPIUz3fji8vmxZG/Da6jx/c
 a0UQdFFCL4Ay/EMSoGbQouzhC69OQLWNH3rMQbBvrRbiMJbEZwARAQABzR9NaWNoYWwgU2lt
 ZWsgPG1vbnN0ckBtb25zdHIuZXU+wsGBBBMBAgArAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIe
 AQIXgAIZAQUCWq+GEgUJDuRkWQAKCRA3fH8h/j0fkW9/D/9IBoykgOWah2BakL43PoHAyEKb
 Wt3QxWZSgQjeV3pBys08uQDxByChT1ZW3wsb30GIQSTlzQ7juacoUosje1ygaLHR4xoFMAT9
 L6F4YzZaPwW6aLI8pUJad63r50sWiGDN/UlhvPrHa3tinhReTEgSCoPCFg3TjjT4nI/NSxUS
 5DAbL9qpJyr+dZNDUNX/WnPSqMc4q5R1JqVUxw2xuKPtH0KI2YMoMZ4BC+qfIM+hz+FTQAzk
 nAfA0/fbNi0gi4050wjouDJIN+EEtgqEewqXPxkJcFd3XHZAXcR7f5Q1oEm1fH3ecyiMJ3ye
 Paim7npOoIB5+wL24BQ7IrMn3NLeFLdFMYZQDSBIUMe4NNyTfvrHPiwZzg2+9Z+OHvR9hv+r
 +u/iQ5t5IJrnZQIHm4zEsW5TD7HaWLDx6Uq/DPUf2NjzKk8lPb1jgWbCUZ0ccecESwpgMg35
 jRxodat/+RkFYBqj7dpxQ91T37RyYgSqKV9EhkIL6F7Whrt9o1cFxhlmTL86hlflPuSs+/Em
 XwYVS+bO454yo7ksc54S+mKhyDQaBpLZBSh/soJTxB/nCOeJUji6HQBGXdWTPbnci1fnUhF0
 iRNmR5lfyrLYKp3CWUrpKmjbfePnUfQS+njvNjQG+gds5qnIk2glCvDsuAM1YXlM5mm5Yh+v
 z47oYKzXe87A4gRRb3+lEQQAsBOQdv8t1nkdEdIXWuD6NPpFewqhTpoFrxUtLnyTb6B+gQ1+
 /nXPT570UwNw58cXr3/HrDml3e3Iov9+SI771jZj9+wYoZiO2qop9xp0QyDNHMucNXiy265e
 OAPA0r2eEAfxZCi8i5D9v9EdKsoQ9jbII8HVnis1Qu4rpuZVjW8AoJ6xN76kn8yT225eRVly
 PnX9vTqjBACUlfoU6cvse3YMCsJuBnBenGYdxczU4WmNkiZ6R0MVYIeh9X0LqqbSPi0gF5/x
 D4azPL01d7tbxmJpwft3FO9gpvDqq6n5l+XHtSfzP7Wgooo2rkuRJBntMCwZdymPwMChiZgh
 kN/sEvsNnZcWyhw2dCcUekV/eu1CGq8+71bSFgP/WPaXAwXfYi541g8rLwBrgohJTE0AYbQD
 q5GNF6sDG/rNQeDMFmr05H+XEbV24zeHABrFpzWKSfVy3+J/hE5eWt9Nf4dyto/S55cS9qGB
 caiED4NXQouDXaSwcZ8hrT34xrf5PqEAW+3bn00RYPFNKzXRwZGQKRDte8aCds+GHufCwa0E
 GAECAA8CGwIFAlqvhnkFCQ7joU8AUgkQN3x/If49H5FHIAQZEQIABgUCUW9/pQAKCRDKSWXL
 KUoMITzqAJ9dDs41goPopjZu2Au7zcWRevKP9gCgjNkNe7MxC9OeNnup6zNeTF0up/nEYw/9
 Httigv2cYu0Q6jlftJ1zUAHadoqwChliMgsbJIQYvRpUYchv+11ZAjcWMlmW/QsS0arrkpA3
 RnXpWg3/Y0kbm9dgqX3edGlBvPsw3gY4HohkwptSTE/h3UHS0hQivelmf4+qUTJZzGuE8TUN
 obSIZOvB4meYv8z1CLy0EVsLIKrzC9N05gr+NP/6u2x0dw0WeLmVEZyTStExbYNiWSpp+SGh
 MTyqDR/lExaRHDCVaveuKRFHBnVf9M5m2O0oFlZefzG5okU3lAvEioNCd2MJQaFNrNn0b0zl
 SjbdfFQoc3m6e6bLtBPfgiA7jLuf5MdngdWaWGti9rfhVL/8FOjyG19agBKcnACYj3a3WCJS
 oi6fQuNboKdTATDMfk9P4lgL94FD/Y769RtIvMHDi6FInfAYJVS7L+BgwTHu6wlkGtO9ZWJj
 ktVy3CyxR0dycPwFPEwiRauKItv/AaYxf6hb5UKAPSE9kHGI4H1bK2R2k77gR2hR1jkooZxZ
 UjICk2bNosqJ4Hidew1mjR0rwTq05m7Z8e8Q0FEQNwuw/GrvSKfKmJ+xpv0rQHLj32/OAvfH
 L+sE5yV0kx0ZMMbEOl8LICs/PyNpx6SXnigRPNIUJH7Xd7LXQfRbSCb3BNRYpbey+zWqY2Wu
 LHR1TS1UI9Qzj0+nOrVqrbV48K4Y78sajt7OwU0EUW68MQEQAJeqJfmHggDTd8k7CH7zZpBZ
 4dUAQOmMPMrmFJIlkMTnko/xuvUVmuCuO9D0xru2FK7WZuv7J14iqg7X+Ix9kD4MM+m+jqSx
 yN6nXVs2FVrQmkeHCcx8c1NIcMyr05cv1lmmS7/45e1qkhLMgfffqnhlRQHlqxp3xTHvSDiC
 Yj3Z4tYHMUV2XJHiDVWKznXU2fjzWWwM70tmErJZ6VuJ/sUoq/incVE9JsG8SCHvVXc0MI+U
 kmiIeJhpLwg3e5qxX9LX5zFVvDPZZxQRkKl4dxjaqxAASqngYzs8XYbqC3Mg4FQyTt+OS7Wb
 OXHjM/u6PzssYlM4DFBQnUceXHcuL7G7agX1W/XTX9+wKam0ABQyjsqImA8u7xOw/WaKCg6h
 JsZQxHSNClRwoXYvaNo1VLq6l282NtGYWiMrbLoD8FzpYAqG12/z97T9lvKJUDv8Q3mmFnUa
 6AwnE4scnV6rDsNDkIdxJDls7HRiOaGDg9PqltbeYHXD4KUCfGEBvIyx8GdfG+9yNYg+cFWU
 HZnRgf+CLMwN0zRJr8cjP6rslHteQYvgxh4AzXmbo7uGQIlygVXsszOQ0qQ6IJncTQlgOwxe
 +aHdLgRVYAb5u4D71t4SUKZcNxc8jg+Kcw+qnCYs1wSE9UxB+8BhGpCnZ+DW9MTIrnwyz7Rr
 0vWTky+9sWD1ABEBAAHCwWUEGAECAA8CGwwFAlqvhmUFCQ7kZLEACgkQN3x/If49H5H4OhAA
 o5VEKY7zv6zgEknm6cXcaARHGH33m0z1hwtjjLfVyLlazarD1VJ79RkKgqtALUd0n/T1Cwm+
 NMp929IsBPpC5Ql3FlgQQsvPL6Ss2BnghoDr4wHVq+0lsaPIRKcQUOOBKqKaagfG2L5zSr3w
 rl9lAZ5YZTQmI4hCyVaRp+x9/l3dma9G68zY5fw1aYuqpqSpV6+56QGpb+4WDMUb0A/o+Xnt
 R//PfnDsh1KH48AGfbdKSMI83IJd3V+N7FVR2BWU1rZ8CFDFAuWj374to8KinC7BsJnQlx7c
 1CzxB6Ht93NvfLaMyRtqgc7Yvg2fKyO/+XzYPOHAwTPM4xrlOmCKZNI4zkPleVeXnrPuyaa8
 LMGqjA52gNsQ5g3rUkhp61Gw7g83rjDDZs5vgZ7Q2x3CdH0mLrQPw2u9QJ8K8OVnXFtiKt8Q
 L3FaukbCKIcP3ogCcTHJ3t75m4+pwH50MM1yQdFgqtLxPgrgn3U7fUVS9x4MPyO57JDFPOG4
 oa0OZXydlVP7wrnJdi3m8DnljxyInPxbxdKGN5XnMq/r9Y70uRVyeqwp97sKLXd9GsxuaSg7
 QJKUaltvN/i7ng1UOT/xsKeVdfXuqDIIElZ+dyEVTweDM011Zv0NN3OWFz6oD+GzyBetuBwD
 0Z1MQlmNcq2bhOMzTxuXX2NDzUZs4aqEyZQ=
Message-ID: <ac2ab6d1-69c9-34aa-6c25-588bacc78002@xilinx.com>
Date:   Thu, 10 Sep 2020 08:49:56 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.12.0
MIME-Version: 1.0
In-Reply-To: <1599693000-25641-1-git-send-email-amit.sunil.dhamne@xilinx.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Sep 2020 06:50:09.4407
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: fec9ad6a-86af-4d4e-9d5e-08d85555c25f
X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c;Ip=[149.199.60.83];Helo=[xsj-pvapsmtpgw01]
X-MS-Exchange-CrossTenant-AuthSource: CY1NAM02FT053.eop-nam02.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR02MB6528
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Arnd,

On 10. 09. 20 1:10, Amit Sunil Dhamne wrote:
> From: Rajan Vaja <rajan.vaja@xilinx.com>
> 
> Initially all devices are in power up state. Firmware expect that
> processor should call InitFinalize API once it have requested devices
> which are required so that it can turn off all unused devices and
> save power. From Linux, PM driver calls InitFinalize to inform the
> firmware that it can power down the unused devices. Upon
> InitFinalize() call firmware power downs all unused devices.
> 
> There are chances that PM driver is probed along with or before other
> device drivers. So in that case some of the devices may not be
> requested from firmware which is done by genpd driver. Due to that
> firmware will consider those devices as unused and firmware will power
> down those devices. Later when any device driver is probed, genpd
> driver will ask firmware to power up that device using request node
> API. So for those devices, power transition will be like on->off->on
> which creates unnecessary power glitch to those devices.
> 
> To avoid such unnecessary power transitions and as ideal behavior
> InitFinalize should be called after all drivers are probed. So call
> InitFinalize from late_initcall_sync.
> 
> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
> Signed-off-by: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com>
> ---
> Changes in v2:
>  - Check for compatible string for zynqmp or versal platform before
>    calling init finalize.
> ---
>  drivers/soc/xilinx/zynqmp_power.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
> index 31ff49f..22d2d2e 100644
> --- a/drivers/soc/xilinx/zynqmp_power.c
> +++ b/drivers/soc/xilinx/zynqmp_power.c
> @@ -178,7 +178,6 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>  	u32 pm_api_version;
>  	struct mbox_client *client;
>  
> -	zynqmp_pm_init_finalize();
>  	zynqmp_pm_get_api_version(&pm_api_version);
>  
>  	/* Check PM API version number */
> @@ -246,6 +245,23 @@ static int zynqmp_pm_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int __init do_init_finalize(void)
> +{
> +	struct device_node *np;
> +
> +	np = of_find_compatible_node(NULL, NULL, "xlnx,zynqmp");
> +	if (!np) {
> +		np = of_find_compatible_node(NULL, NULL, "xlnx,versal");
> +		if (!np)
> +			return 0;
> +	}
> +	of_node_put(np);
> +
> +	return zynqmp_pm_init_finalize();
> +}
> +
> +late_initcall_sync(do_init_finalize);
> +
>  static const struct of_device_id pm_of_match[] = {
>  	{ .compatible = "xlnx,zynqmp-power", },
>  	{ /* end of table */ },
> 

Arnd: are you fine with this way how to check that it runs on zynqmp or
versal?

Thanks,
Michal