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Subject: Re: [PATCH v2 2/7] PCI: ACPI: PM: Do not use pci_platform_pm_ops for
 ACPI
To:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Linux PCI <linux-pci@vger.kernel.org>
Cc:     Linux ACPI <linux-acpi@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>
References: <1800633.tdWV9SEqCh@kreacher> <8879480.rMLUfLXkoz@kreacher>
From:   Ferry Toth <fntoth@gmail.com>
Message-ID: <069444f7-d623-fae2-5cd0-83cbbc919aff@gmail.com>
Date:   Wed, 22 Sep 2021 23:30:58 +0200
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Hi,
Op 20-09-2021 om 21:17 schreef Rafael J. Wysocki:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Using struct pci_platform_pm_ops for ACPI adds unnecessary
> indirection to the interactions between the PCI core and ACPI PM,
> which is also subject to retpolines.
> 
> Moreover, it is not particularly clear from the current code that,
> as far as PCI PM is concerned, "platform" really means just ACPI
> except for the special casess when Intel MID PCI PM is used or when
> ACPI support is disabled (through the kernel config or command line,
> or because there are no usable ACPI tables on the system).
> 
> To address the above, rework the PCI PM code to invoke ACPI PM
> functions directly as needed and drop the acpi_pci_platform_pm
> object that is not necessary any more.
> 
> Accordingly, update some of the ACPI PM functions in question to do
> extra checks in case the ACPI support is disabled (which previously
> was taken care of by avoiding to set the pci_platform_ops pointer
> in those cases).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> 
> v1 -> v2:
>      * Rebase on top of the new [1/7] and move dropping struct
>        pci_platform_pm_ops to a separate patch.

I wanted to test this series on 5.15-rc2 but this patch 2/7 doesn't 
apply (after 1/7 applied). Should I apply this on another tree?

> ---
>   drivers/pci/pci-acpi.c |   42 ++++++++++++++++++++----------------------
>   drivers/pci/pci.c      |   22 +++++++++-------------
>   drivers/pci/pci.h      |   38 +++++++++++++++++++++++++++++++++++++-
>   3 files changed, 66 insertions(+), 36 deletions(-)
> 
> Index: linux-pm/drivers/pci/pci-acpi.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci-acpi.c
> +++ linux-pm/drivers/pci/pci-acpi.c
> @@ -906,10 +906,13 @@ acpi_status pci_acpi_add_pm_notifier(str
>    *	choose highest power _SxD or any lower power
>    */
>   
> -static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
> +pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
>   {
>   	int acpi_state, d_max;
>   
> +	if (acpi_pci_disabled)
> +		return PCI_POWER_ERROR;
> +
>   	if (pdev->no_d3cold)
>   		d_max = ACPI_STATE_D3_HOT;
>   	else
> @@ -965,7 +968,7 @@ int pci_dev_acpi_reset(struct pci_dev *d
>   	return 0;
>   }
>   
> -static bool acpi_pci_power_manageable(struct pci_dev *dev)
> +bool acpi_pci_power_manageable(struct pci_dev *dev)
>   {
>   	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
>   
> @@ -974,13 +977,13 @@ static bool acpi_pci_power_manageable(st
>   	return acpi_device_power_manageable(adev);
>   }
>   
> -static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> +bool acpi_pci_bridge_d3(struct pci_dev *dev)
>   {
>   	const union acpi_object *obj;
>   	struct acpi_device *adev;
>   	struct pci_dev *rpdev;
>   
> -	if (!dev->is_hotplug_bridge)
> +	if (acpi_pci_disabled || !dev->is_hotplug_bridge)
>   		return false;
>   
>   	/* Assume D3 support if the bridge is power-manageable by ACPI. */
> @@ -1008,7 +1011,7 @@ static bool acpi_pci_bridge_d3(struct pc
>   	return obj->integer.value == 1;
>   }
>   
> -static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
> +int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
>   {
>   	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
>   	static const u8 state_conv[] = {
> @@ -1046,7 +1049,7 @@ static int acpi_pci_set_power_state(stru
>   	return error;
>   }
>   
> -static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
> +pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
>   {
>   	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
>   	static const pci_power_t state_conv[] = {
> @@ -1068,7 +1071,7 @@ static pci_power_t acpi_pci_get_power_st
>   	return state_conv[state];
>   }
>   
> -static void acpi_pci_refresh_power_state(struct pci_dev *dev)
> +void acpi_pci_refresh_power_state(struct pci_dev *dev)
>   {
>   	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
>   
> @@ -1093,17 +1096,23 @@ static int acpi_pci_propagate_wakeup(str
>   	return 0;
>   }
>   
> -static int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
> +int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
>   {
> +	if (acpi_pci_disabled)
> +		return 0;
> +
>   	if (acpi_pm_device_can_wakeup(&dev->dev))
>   		return acpi_pm_set_device_wakeup(&dev->dev, enable);
>   
>   	return acpi_pci_propagate_wakeup(dev->bus, enable);
>   }
>   
> -static bool acpi_pci_need_resume(struct pci_dev *dev)
> +bool acpi_pci_need_resume(struct pci_dev *dev)
>   {
> -	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
> +	struct acpi_device *adev;
> +
> +	if (acpi_pci_disabled)
> +		return false;
>   
>   	/*
>   	 * In some cases (eg. Samsung 305V4A) leaving a bridge in suspend over
> @@ -1118,6 +1127,7 @@ static bool acpi_pci_need_resume(struct
>   	if (!adev || !acpi_device_power_manageable(adev))
>   		return false;
>   
> +	adev = ACPI_COMPANION(&dev->dev);
>   	if (adev->wakeup.flags.valid &&
>   	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
>   		return true;
> @@ -1128,17 +1138,6 @@ static bool acpi_pci_need_resume(struct
>   	return !!adev->power.flags.dsw_present;
>   }
>   
> -static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
> -	.bridge_d3 = acpi_pci_bridge_d3,
> -	.is_manageable = acpi_pci_power_manageable,
> -	.set_state = acpi_pci_set_power_state,
> -	.get_state = acpi_pci_get_power_state,
> -	.refresh_state = acpi_pci_refresh_power_state,
> -	.choose_state = acpi_pci_choose_state,
> -	.set_wakeup = acpi_pci_wakeup,
> -	.need_resume = acpi_pci_need_resume,
> -};
> -
>   void acpi_pci_add_bus(struct pci_bus *bus)
>   {
>   	union acpi_object *obj;
> @@ -1448,7 +1447,6 @@ static int __init acpi_pci_init(void)
>   	if (acpi_pci_disabled)
>   		return 0;
>   
> -	pci_set_platform_pm(&acpi_pci_platform_pm);
>   	acpi_pci_slot_init();
>   	acpiphp_init();
>   
> Index: linux-pm/drivers/pci/pci.h
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.h
> +++ linux-pm/drivers/pci/pci.h
> @@ -725,17 +725,53 @@ int pci_acpi_program_hp_params(struct pc
>   extern const struct attribute_group pci_dev_acpi_attr_group;
>   void pci_set_acpi_fwnode(struct pci_dev *dev);
>   int pci_dev_acpi_reset(struct pci_dev *dev, bool probe);
> +bool acpi_pci_power_manageable(struct pci_dev *dev);
> +bool acpi_pci_bridge_d3(struct pci_dev *dev);
> +int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state);
> +pci_power_t acpi_pci_get_power_state(struct pci_dev *dev);
> +void acpi_pci_refresh_power_state(struct pci_dev *dev);
> +int acpi_pci_wakeup(struct pci_dev *dev, bool enable);
> +bool acpi_pci_need_resume(struct pci_dev *dev);
> +pci_power_t acpi_pci_choose_state(struct pci_dev *pdev);
>   #else
>   static inline int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
>   {
>   	return -ENOTTY;
>   }
> -
>   static inline void pci_set_acpi_fwnode(struct pci_dev *dev) {}
>   static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
>   {
>   	return -ENODEV;
>   }
> +static inline bool acpi_pci_power_manageable(struct pci_dev *dev)
> +{
> +	return false;
> +}
> +static inline bool acpi_pci_bridge_d3(struct pci_dev *dev)
> +{
> +	return false;
> +}
> +static inline int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
> +{
> +	return -ENODEV;
> +}
> +static inline pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
> +{
> +	return PCI_UNKNOWN;
> +}
> +static inline void acpi_pci_refresh_power_state(struct pci_dev *dev) {}
> +static inline int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
> +{
> +	return -ENODEV;
> +}
> +static inline bool acpi_pci_need_resume(struct pci_dev *dev)
> +{
> +	return false;
> +}
> +static inline pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
> +{
> +	return PCI_POWER_ERROR;
> +}
>   #endif
>   
>   #ifdef CONFIG_PCIEASPM
> Index: linux-pm/drivers/pci/pci.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.c
> +++ linux-pm/drivers/pci/pci.c
> @@ -988,7 +988,7 @@ static inline bool platform_pci_power_ma
>   	if (pci_use_mid_pm())
>   		return true;
>   
> -	return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false;
> +	return acpi_pci_power_manageable(dev);
>   }
>   
>   static inline int platform_pci_set_power_state(struct pci_dev *dev,
> @@ -997,7 +997,7 @@ static inline int platform_pci_set_power
>   	if (pci_use_mid_pm())
>   		return mid_pci_set_power_state(dev, t);
>   
> -	return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS;
> +	return acpi_pci_set_power_state(dev, t);
>   }
>   
>   static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
> @@ -1005,13 +1005,13 @@ static inline pci_power_t platform_pci_g
>   	if (pci_use_mid_pm())
>   		return mid_pci_get_power_state(dev);
>   
> -	return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN;
> +	return acpi_pci_get_power_state(dev);
>   }
>   
>   static inline void platform_pci_refresh_power_state(struct pci_dev *dev)
>   {
> -	if (!pci_use_mid_pm() && pci_platform_pm && pci_platform_pm->refresh_state)
> -		pci_platform_pm->refresh_state(dev);
> +	if (!pci_use_mid_pm())
> +		acpi_pci_refresh_power_state(dev);
>   }
>   
>   static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
> @@ -1019,8 +1019,7 @@ static inline pci_power_t platform_pci_c
>   	if (pci_use_mid_pm())
>   		return PCI_POWER_ERROR;
>   
> -	return pci_platform_pm ?
> -			pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
> +	return acpi_pci_choose_state(dev);
>   }
>   
>   static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
> @@ -1028,8 +1027,7 @@ static inline int platform_pci_set_wakeu
>   	if (pci_use_mid_pm())
>   		return PCI_POWER_ERROR;
>   
> -	return pci_platform_pm ?
> -			pci_platform_pm->set_wakeup(dev, enable) : -ENODEV;
> +	return acpi_pci_wakeup(dev, enable);
>   }
>   
>   static inline bool platform_pci_need_resume(struct pci_dev *dev)
> @@ -1037,7 +1035,7 @@ static inline bool platform_pci_need_res
>   	if (pci_use_mid_pm())
>   		return false;
>   
> -	return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false;
> +	return acpi_pci_need_resume(dev);
>   }
>   
>   static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
> @@ -1045,9 +1043,7 @@ static inline bool platform_pci_bridge_d
>   	if (pci_use_mid_pm())
>   		return false;
>   
> -	if (pci_platform_pm && pci_platform_pm->bridge_d3)
> -		return pci_platform_pm->bridge_d3(dev);
> -	return false;
> +	return acpi_pci_bridge_d3(dev);
>   }
>   
>   /**
> 
> 
>