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Date:   Thu, 27 Apr 2023 11:48:16 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Mario Limonciello <mario.limonciello@amd.com>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Shyam Sundar S K <Shyam-sundar.S-k@amd.com>,
        Sanket Goswami <Sanket.Goswami@amd.com>,
        Richard gong <richard.gong@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: Re: [PATCH 1/2] amd_nb: Add PCI ID for family 19h model 78h
Message-ID: <20230427164816.GA255750@bhelgaas>
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In-Reply-To: <20230427053338.16653-2-mario.limonciello@amd.com>
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On Thu, Apr 27, 2023 at 12:33:36AM -0500, Mario Limonciello wrote:
> s2idle previously worked on this system, but it regressed in kernel
> 6.4 due to commit 310e782a99c7 ("platform/x86/amd: pmc: Utilize SMN
> index 0 for driver probe").
> 
> The reason for the regression is that before this commit the SMN
> communication was hardcoded, but after amd_smn_read() is used which
> relies upon the misc PCI ID used by DF function 3 being included in
> a table.  The ID was missing for model 78h, so this meant that the
> amd_smn_read() wouldn't work.
> 
> Add the missing ID into amd_nb, restoring s2idle on this system.
> 
> Fixes: 310e782a99c7 ("platform/x86/amd: pmc: Utilize SMN index 0 for driver probe")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Grudgingly, because this really isn't a maintainable strategy:

Acked-by: Bjorn Helgaas <bhelgaas@google.com>  # pci_ids.h

> ---
>  arch/x86/kernel/amd_nb.c | 2 ++
>  include/linux/pci_ids.h  | 1 +
>  2 files changed, 3 insertions(+)
> 
> diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
> index 4266b64631a4..7e331e8f3692 100644
> --- a/arch/x86/kernel/amd_nb.c
> +++ b/arch/x86/kernel/amd_nb.c
> @@ -36,6 +36,7 @@
>  #define PCI_DEVICE_ID_AMD_19H_M50H_DF_F4 0x166e
>  #define PCI_DEVICE_ID_AMD_19H_M60H_DF_F4 0x14e4
>  #define PCI_DEVICE_ID_AMD_19H_M70H_DF_F4 0x14f4
> +#define PCI_DEVICE_ID_AMD_19H_M78H_DF_F4 0x12fc
>  
>  /* Protect the PCI config register pairs used for SMN. */
>  static DEFINE_MUTEX(smn_mutex);
> @@ -79,6 +80,7 @@ static const struct pci_device_id amd_nb_misc_ids[] = {
>  	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M50H_DF_F3) },
>  	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M60H_DF_F3) },
>  	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M70H_DF_F3) },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_19H_M78H_DF_F3) },
>  	{}
>  };
>  
> diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
> index 45c3d62e616d..95f33dadb2be 100644
> --- a/include/linux/pci_ids.h
> +++ b/include/linux/pci_ids.h
> @@ -567,6 +567,7 @@
>  #define PCI_DEVICE_ID_AMD_19H_M50H_DF_F3 0x166d
>  #define PCI_DEVICE_ID_AMD_19H_M60H_DF_F3 0x14e3
>  #define PCI_DEVICE_ID_AMD_19H_M70H_DF_F3 0x14f3
> +#define PCI_DEVICE_ID_AMD_19H_M78H_DF_F3 0x12fb
>  #define PCI_DEVICE_ID_AMD_CNB17H_F3	0x1703
>  #define PCI_DEVICE_ID_AMD_LANCE		0x2000
>  #define PCI_DEVICE_ID_AMD_LANCE_HOME	0x2001
> -- 
> 2.34.1
>