linux-kernel - Re: [PATCH 1/1] platform/x86/amd: pmc: Read SMU version during suspend on Cezanne systems

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Date:   Mon, 24 Oct 2022 11:29:47 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Mario Limonciello <mario.limonciello@....com>,
        Shyam Sundar S K <Shyam-sundar.S-k@....com>
Cc:     Anson Tsao <anson.tsao@....com>,
        You-Sheng Yang <vicamo.yang@...onical.com>,
        stable@...r.kernel.org, Mark Gross <markgross@...nel.org>,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] platform/x86/amd: pmc: Read SMU version during
 suspend on Cezanne systems

Hi,

On 10/20/22 13:37, Mario Limonciello wrote:
> commit b0c07116c8943 ("platform/x86: amd-pmc: Avoid reading SMU version at
> probe time") adjusted the behavior for amd-pmc to avoid reading the SMU version
> at startup but rather on first use to improve boot time.
> 
> However the SMU version is also used to decide whether to place a timer based
> wakeup in the OS_HINT message.  If the idlemask hasn't been read before this
> message was sent then the SMU version will not have been cached.
> 
> Ensure the SMU version has been read before deciding whether or not to run this
> codepath.
> 
> Cc: stable@...r.kernel.org # 6.0
> Reported-by: You-Sheng Yang <vicamo.yang@...onical.com>
> Tested-by: Anson Tsao <anson.tsao@....com>
> Fixes: b0c07116c8943 ("platform/x86: amd-pmc: Avoid reading SMU version at probe time")
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>

Thank you for your patch, I've applied this patch to my review-hans 
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans


> ---
>  drivers/platform/x86/amd/pmc.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/platform/x86/amd/pmc.c b/drivers/platform/x86/amd/pmc.c
> index ce859b300712b..96e790e639a21 100644
> --- a/drivers/platform/x86/amd/pmc.c
> +++ b/drivers/platform/x86/amd/pmc.c
> @@ -663,6 +663,13 @@ static int amd_pmc_verify_czn_rtc(struct amd_pmc_dev *pdev, u32 *arg)
>  	struct rtc_time tm;
>  	int rc;
>  
> +	/* we haven't yet read SMU version */
> +	if (!pdev->major) {
> +		rc = amd_pmc_get_smu_version(pdev);
> +		if (rc)
> +			return rc;
> +	}
> +
>  	if (pdev->major < 64 || (pdev->major == 64 && pdev->minor < 53))
>  		return 0;
>