[V2,8/9] PCI: tegra: Broadcast PME_turn_Off message before link goes to L2

Message ID 1511638333-22951-9-git-send-email-mmaddireddy@nvidia.com
State Superseded
Headers show
Series
  • Add loadable kernel module and power management support
Related show

Commit Message

Manikanta Maddireddy Nov. 25, 2017, 7:32 p.m.
Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast PME_turn_Off
message before PCIe link goes to L2. PME_turn_Off broadcast mechanism is
implemented in AFI module. Each Tegra PCIe root port has its own
PME_turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
register to broadcast PME_turn_Off message.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
V2:
* no change in this patch

 drivers/pci/host/pci-tegra.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

Comments

Mikko Perttunen Nov. 29, 2017, 12:18 p.m. | #1
On 25.11.2017 21:32, Manikanta Maddireddy wrote:
> Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast PME_turn_Off
> message before PCIe link goes to L2. PME_turn_Off broadcast mechanism is
> implemented in AFI module. Each Tegra PCIe root port has its own
> PME_turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
> register to broadcast PME_turn_Off message.
>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> ---
> V2:
> * no change in this patch
>
>  drivers/pci/host/pci-tegra.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 76 insertions(+)
>
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index bbc2807bcd4a..b380958a3deb 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -155,6 +155,8 @@
>  #define  AFI_INTR_EN_FPCI_TIMEOUT	(1 << 7)
>  #define  AFI_INTR_EN_PRSNT_SENSE	(1 << 8)
>
> +#define AFI_PCIE_PME		0xf0
> +
>  #define AFI_PCIE_CONFIG					0x0f8
>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE(x)		(1 << ((x) + 1))
>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE_ALL		0xe
> @@ -315,6 +317,7 @@
>  #define PADS_REFCLK_CFG_DRVI_SHIFT		12 /* 15:12 */
>
>  #define LINK_RETRAIN_TIMEOUT 100000
> +#define PME_ACK_TIMEOUT 10000
>
>  struct tegra_msi {
>  	struct msi_controller chip;
> @@ -1503,6 +1506,76 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
>  	return 0;
>  }
>
> +static inline u32 get_pme_turnoff_bitmap(struct tegra_pcie_port *port)
> +{
> +	struct device *dev = port->pcie->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret = 0;
> +
> +	switch (port->index) {
> +	case 0:
> +		ret = 0;
> +	case 1:
> +		ret = 8;
> +	case 2:
> +		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
> +			ret = 16;
> +		else
> +			ret = 12;
> +	}
> +	return ret;
> +}
> +
> +static inline u32 get_pme_ack_bitmap(struct tegra_pcie_port *port)
> +{
> +	struct device *dev = port->pcie->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret = 0;
> +
> +	switch (port->index) {
> +	case 0:
> +		ret = 5;
> +	case 1:
> +		ret = 10;
> +	case 2:
> +		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
> +			ret = 18;
> +		else
> +			ret = 14;
> +	}
> +	return ret;
> +}

 From what I can tell, the port 2 bit is 12/14 on everything after 
Tegra30 as well, so I don't think this actually works?

I think simpler would be to add a SoC data fields 'u8 
pme_turnoff_bit[3]' and 'u8 pme_ack_bit[3]' and then set that
to '.pme_turnoff_bit = { 0, 8, 16 }' and so on.

> +
> +static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
> +{
> +	struct tegra_pcie *pcie = port->pcie;
> +	ktime_t deadline;
> +	unsigned int data;
> +
> +	data = afi_readl(pcie, AFI_PCIE_PME);
> +	data |= (0x1 << get_pme_turnoff_bitmap(port));
> +	afi_writel(pcie, data, AFI_PCIE_PME);
> +
> +	deadline = ktime_add_us(ktime_get(), PME_ACK_TIMEOUT);
> +	do {
> +		data = afi_readl(pcie, AFI_PCIE_PME);
> +		data &= (0x1 << get_pme_ack_bitmap(port));
> +		udelay(1);
> +		if (ktime_after(ktime_get(), deadline))
> +			break;
> +	} while (!data);

Since this is a normal MMIO read, we could replace the whole loop with a 
call to readl_poll_timeout (or readl_relaxed_poll_timeout, or if we 
really must delay and not sleep, readl_poll_timeout_atomic etc.) from 
iopoll.h

   int err;
   u32 val;

   err = readl_poll_timeout(pcie->afi + AFI_PCIE_PME, val,
                            val & (0x1 << pcie->soc->pme_ack_bit[port]),
                            1, PME_ACK_TIMEOUT);
   if (err)
     ...

> +
> +	if (data)
> +		dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",
> +			port->index);
> +

Typo here, s/receieved/received/

Cheers,
Mikko

> +	usleep_range(10000, 11000);
> +
> +	data = afi_readl(pcie, AFI_PCIE_PME);
> +	data &= ~(0x1 << get_pme_turnoff_bitmap(port));
> +	afi_writel(pcie, data, AFI_PCIE_PME);
> +}
> +
>  static int tegra_msi_alloc(struct tegra_msi *chip)
>  {
>  	int msi;
> @@ -2828,6 +2901,7 @@ static int tegra_pcie_remove(struct platform_device *pdev)
>  {
>  	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
>  	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
> +	struct tegra_pcie_port *port, *tmp;
>
>  	if (IS_ENABLED(CONFIG_DEBUG_FS))
>  		tegra_pcie_debugfs_exit(pcie);
> @@ -2835,6 +2909,8 @@ static int tegra_pcie_remove(struct platform_device *pdev)
>  	pci_remove_root_bus(host->bus);
>  	if (IS_ENABLED(CONFIG_PCI_MSI))
>  		tegra_pcie_disable_msi(pcie);
> +	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
> +		tegra_pcie_pme_turnoff(port);
>  	tegra_pcie_disable_ports(pcie);
>  	tegra_pcie_free_resources(pcie);
>  	tegra_pcie_disable_controller(pcie);
>
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Bjorn Helgaas Nov. 29, 2017, 4:51 p.m. | #2
On Sun, Nov 26, 2017 at 01:02:12AM +0530, Manikanta Maddireddy wrote:
> Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast PME_turn_Off
> message before PCIe link goes to L2. PME_turn_Off broadcast mechanism is
> implemented in AFI module. Each Tegra PCIe root port has its own
> PME_turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
> register to broadcast PME_turn_Off message.

s/PME_turn_Off/PME_Turn_Off/ above to match spec.

I thought PME_TO_Ack was also mis-capitalized, but it's not.  Guess
that "TO" stands for "Turn Off".

> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> ---
> V2:
> * no change in this patch
> 
>  drivers/pci/host/pci-tegra.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 76 insertions(+)
> 
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index bbc2807bcd4a..b380958a3deb 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -155,6 +155,8 @@
>  #define  AFI_INTR_EN_FPCI_TIMEOUT	(1 << 7)
>  #define  AFI_INTR_EN_PRSNT_SENSE	(1 << 8)
>  
> +#define AFI_PCIE_PME		0xf0
> +
>  #define AFI_PCIE_CONFIG					0x0f8
>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE(x)		(1 << ((x) + 1))
>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE_ALL		0xe
> @@ -315,6 +317,7 @@
>  #define PADS_REFCLK_CFG_DRVI_SHIFT		12 /* 15:12 */
>  
>  #define LINK_RETRAIN_TIMEOUT 100000
> +#define PME_ACK_TIMEOUT 10000
>  
>  struct tegra_msi {
>  	struct msi_controller chip;
> @@ -1503,6 +1506,76 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
>  	return 0;
>  }
>  
> +static inline u32 get_pme_turnoff_bitmap(struct tegra_pcie_port *port)
> +{
> +	struct device *dev = port->pcie->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret = 0;

Unnecessary initialization.  In fact, the variable is unnecessary; you
can just return the value directly as soon as you know it.

> +
> +	switch (port->index) {
> +	case 0:
> +		ret = 0;
> +	case 1:
> +		ret = 8;
> +	case 2:
> +		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
> +			ret = 16;
> +		else
> +			ret = 12;
> +	}
> +	return ret;
> +}
> +
> +static inline u32 get_pme_ack_bitmap(struct tegra_pcie_port *port)
> +{
> +	struct device *dev = port->pcie->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret = 0;

Similar.

> +
> +	switch (port->index) {
> +	case 0:
> +		ret = 5;
> +	case 1:
> +		ret = 10;
> +	case 2:
> +		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
> +			ret = 18;
> +		else
> +			ret = 14;
> +	}
> +	return ret;
> +}
> +
> +static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
> +{
> +	struct tegra_pcie *pcie = port->pcie;
> +	ktime_t deadline;
> +	unsigned int data;
> +
> +	data = afi_readl(pcie, AFI_PCIE_PME);
> +	data |= (0x1 << get_pme_turnoff_bitmap(port));
> +	afi_writel(pcie, data, AFI_PCIE_PME);
> +
> +	deadline = ktime_add_us(ktime_get(), PME_ACK_TIMEOUT);
> +	do {
> +		data = afi_readl(pcie, AFI_PCIE_PME);
> +		data &= (0x1 << get_pme_ack_bitmap(port));
> +		udelay(1);
> +		if (ktime_after(ktime_get(), deadline))
> +			break;
> +	} while (!data);
> +
> +	if (data)
> +		dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",

s/receieved/received/

> +			port->index);
> +
> +	usleep_range(10000, 11000);
> +
> +	data = afi_readl(pcie, AFI_PCIE_PME);
> +	data &= ~(0x1 << get_pme_turnoff_bitmap(port));
> +	afi_writel(pcie, data, AFI_PCIE_PME);
> +}
> +
>  static int tegra_msi_alloc(struct tegra_msi *chip)
>  {
>  	int msi;
> @@ -2828,6 +2901,7 @@ static int tegra_pcie_remove(struct platform_device *pdev)
>  {
>  	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
>  	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
> +	struct tegra_pcie_port *port, *tmp;
>  
>  	if (IS_ENABLED(CONFIG_DEBUG_FS))
>  		tegra_pcie_debugfs_exit(pcie);
> @@ -2835,6 +2909,8 @@ static int tegra_pcie_remove(struct platform_device *pdev)
>  	pci_remove_root_bus(host->bus);
>  	if (IS_ENABLED(CONFIG_PCI_MSI))
>  		tegra_pcie_disable_msi(pcie);
> +	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
> +		tegra_pcie_pme_turnoff(port);
>  	tegra_pcie_disable_ports(pcie);
>  	tegra_pcie_free_resources(pcie);
>  	tegra_pcie_disable_controller(pcie);
> -- 
> 2.1.4
> 
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Manikanta Maddireddy Nov. 30, 2017, 6:43 p.m. | #3
On 29-Nov-17 10:21 PM, Bjorn Helgaas wrote:
> On Sun, Nov 26, 2017 at 01:02:12AM +0530, Manikanta Maddireddy wrote:
>> Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast PME_turn_Off
>> message before PCIe link goes to L2. PME_turn_Off broadcast mechanism is
>> implemented in AFI module. Each Tegra PCIe root port has its own
>> PME_turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
>> register to broadcast PME_turn_Off message.
> 
> s/PME_turn_Off/PME_Turn_Off/ above to match spec.
> 
> I thought PME_TO_Ack was also mis-capitalized, but it's not.  Guess
> that "TO" stands for "Turn Off".
> 
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> ---
>> V2:
>> * no change in this patch
>>
>>  drivers/pci/host/pci-tegra.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 76 insertions(+)
>>
>> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
>> index bbc2807bcd4a..b380958a3deb 100644
>> --- a/drivers/pci/host/pci-tegra.c
>> +++ b/drivers/pci/host/pci-tegra.c
>> @@ -155,6 +155,8 @@
>>  #define  AFI_INTR_EN_FPCI_TIMEOUT	(1 << 7)
>>  #define  AFI_INTR_EN_PRSNT_SENSE	(1 << 8)
>>  
>> +#define AFI_PCIE_PME		0xf0
>> +
>>  #define AFI_PCIE_CONFIG					0x0f8
>>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE(x)		(1 << ((x) + 1))
>>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE_ALL		0xe
>> @@ -315,6 +317,7 @@
>>  #define PADS_REFCLK_CFG_DRVI_SHIFT		12 /* 15:12 */
>>  
>>  #define LINK_RETRAIN_TIMEOUT 100000
>> +#define PME_ACK_TIMEOUT 10000
>>  
>>  struct tegra_msi {
>>  	struct msi_controller chip;
>> @@ -1503,6 +1506,76 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
>>  	return 0;
>>  }
>>  
>> +static inline u32 get_pme_turnoff_bitmap(struct tegra_pcie_port *port)
>> +{
>> +	struct device *dev = port->pcie->dev;
>> +	struct device_node *np = dev->of_node;
>> +	int ret = 0;
> 
> Unnecessary initialization.  In fact, the variable is unnecessary; you
> can just return the value directly as soon as you know it.
>
I can get rid of this function with Mikko's suggestion to use soc data
 
>> +
>> +	switch (port->index) {
>> +	case 0:
>> +		ret = 0;
>> +	case 1:
>> +		ret = 8;
>> +	case 2:
>> +		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
>> +			ret = 16;
>> +		else
>> +			ret = 12;
>> +	}
>> +	return ret;
>> +}
>> +
>> +static inline u32 get_pme_ack_bitmap(struct tegra_pcie_port *port)
>> +{
>> +	struct device *dev = port->pcie->dev;
>> +	struct device_node *np = dev->of_node;
>> +	int ret = 0;
> 
> Similar.
>
Similar
 
>> +
>> +	switch (port->index) {
>> +	case 0:
>> +		ret = 5;
>> +	case 1:
>> +		ret = 10;
>> +	case 2:
>> +		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
>> +			ret = 18;
>> +		else
>> +			ret = 14;
>> +	}
>> +	return ret;
>> +}
>> +
>> +static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
>> +{
>> +	struct tegra_pcie *pcie = port->pcie;
>> +	ktime_t deadline;
>> +	unsigned int data;
>> +
>> +	data = afi_readl(pcie, AFI_PCIE_PME);
>> +	data |= (0x1 << get_pme_turnoff_bitmap(port));
>> +	afi_writel(pcie, data, AFI_PCIE_PME);
>> +
>> +	deadline = ktime_add_us(ktime_get(), PME_ACK_TIMEOUT);
>> +	do {
>> +		data = afi_readl(pcie, AFI_PCIE_PME);
>> +		data &= (0x1 << get_pme_ack_bitmap(port));
>> +		udelay(1);
>> +		if (ktime_after(ktime_get(), deadline))
>> +			break;
>> +	} while (!data);
>> +
>> +	if (data)
>> +		dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",
> 
> s/receieved/received/
> 
>> +			port->index);
>> +
>> +	usleep_range(10000, 11000);
>> +
>> +	data = afi_readl(pcie, AFI_PCIE_PME);
>> +	data &= ~(0x1 << get_pme_turnoff_bitmap(port));
>> +	afi_writel(pcie, data, AFI_PCIE_PME);
>> +}
>> +
>>  static int tegra_msi_alloc(struct tegra_msi *chip)
>>  {
>>  	int msi;
>> @@ -2828,6 +2901,7 @@ static int tegra_pcie_remove(struct platform_device *pdev)
>>  {
>>  	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
>>  	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
>> +	struct tegra_pcie_port *port, *tmp;
>>  
>>  	if (IS_ENABLED(CONFIG_DEBUG_FS))
>>  		tegra_pcie_debugfs_exit(pcie);
>> @@ -2835,6 +2909,8 @@ static int tegra_pcie_remove(struct platform_device *pdev)
>>  	pci_remove_root_bus(host->bus);
>>  	if (IS_ENABLED(CONFIG_PCI_MSI))
>>  		tegra_pcie_disable_msi(pcie);
>> +	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
>> +		tegra_pcie_pme_turnoff(port);
>>  	tegra_pcie_disable_ports(pcie);
>>  	tegra_pcie_free_resources(pcie);
>>  	tegra_pcie_disable_controller(pcie);
>> -- 
>> 2.1.4
>>
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Mikko Perttunen Dec. 1, 2017, 8:51 a.m. | #4
On 29.11.2017 14:18, Mikko Perttunen wrote:
> On 25.11.2017 21:32, Manikanta Maddireddy wrote:
>> Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast
>> PME_turn_Off
>> message before PCIe link goes to L2. PME_turn_Off broadcast mechanism is
>> implemented in AFI module. Each Tegra PCIe root port has its own
>> PME_turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
>> register to broadcast PME_turn_Off message.
>>
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> ---
>> V2:
>> * no change in this patch
>>
>>  drivers/pci/host/pci-tegra.c | 76
>> ++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 76 insertions(+)
>>
>> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
>> index bbc2807bcd4a..b380958a3deb 100644
>> --- a/drivers/pci/host/pci-tegra.c
>> +++ b/drivers/pci/host/pci-tegra.c
>> @@ -155,6 +155,8 @@
>>  #define  AFI_INTR_EN_FPCI_TIMEOUT    (1 << 7)
>>  #define  AFI_INTR_EN_PRSNT_SENSE    (1 << 8)
>>
>> +#define AFI_PCIE_PME        0xf0
>> +
>>  #define AFI_PCIE_CONFIG                    0x0f8
>>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE(x)        (1 << ((x) + 1))
>>  #define  AFI_PCIE_CONFIG_PCIE_DISABLE_ALL        0xe
>> @@ -315,6 +317,7 @@
>>  #define PADS_REFCLK_CFG_DRVI_SHIFT        12 /* 15:12 */
>>
>>  #define LINK_RETRAIN_TIMEOUT 100000
>> +#define PME_ACK_TIMEOUT 10000
>>
>>  struct tegra_msi {
>>      struct msi_controller chip;
>> @@ -1503,6 +1506,76 @@ static int tegra_pcie_put_resources(struct
>> tegra_pcie *pcie)
>>      return 0;
>>  }
>>
>> +static inline u32 get_pme_turnoff_bitmap(struct tegra_pcie_port *port)
>> +{
>> +    struct device *dev = port->pcie->dev;
>> +    struct device_node *np = dev->of_node;
>> +    int ret = 0;
>> +
>> +    switch (port->index) {
>> +    case 0:
>> +        ret = 0;
>> +    case 1:
>> +        ret = 8;
>> +    case 2:
>> +        if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
>> +            ret = 16;
>> +        else
>> +            ret = 12;
>> +    }
>> +    return ret;
>> +}
>> +
>> +static inline u32 get_pme_ack_bitmap(struct tegra_pcie_port *port)
>> +{
>> +    struct device *dev = port->pcie->dev;
>> +    struct device_node *np = dev->of_node;
>> +    int ret = 0;
>> +
>> +    switch (port->index) {
>> +    case 0:
>> +        ret = 5;
>> +    case 1:
>> +        ret = 10;
>> +    case 2:
>> +        if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
>> +            ret = 18;
>> +        else
>> +            ret = 14;
>> +    }
>> +    return ret;
>> +}
>
> From what I can tell, the port 2 bit is 12/14 on everything after
> Tegra30 as well, so I don't think this actually works?

Looks like I misread this and it is correct, sorry :)
Still the below applies.

Thanks,
Mikko

>
> I think simpler would be to add a SoC data fields 'u8
> pme_turnoff_bit[3]' and 'u8 pme_ack_bit[3]' and then set that
> to '.pme_turnoff_bit = { 0, 8, 16 }' and so on.
>
>> +
>> +static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
>> +{
>> +    struct tegra_pcie *pcie = port->pcie;
>> +    ktime_t deadline;
>> +    unsigned int data;
>> +
>> +    data = afi_readl(pcie, AFI_PCIE_PME);
>> +    data |= (0x1 << get_pme_turnoff_bitmap(port));
>> +    afi_writel(pcie, data, AFI_PCIE_PME);
>> +
>> +    deadline = ktime_add_us(ktime_get(), PME_ACK_TIMEOUT);
>> +    do {
>> +        data = afi_readl(pcie, AFI_PCIE_PME);
>> +        data &= (0x1 << get_pme_ack_bitmap(port));
>> +        udelay(1);
>> +        if (ktime_after(ktime_get(), deadline))
>> +            break;
>> +    } while (!data);
>
> Since this is a normal MMIO read, we could replace the whole loop with a
> call to readl_poll_timeout (or readl_relaxed_poll_timeout, or if we
> really must delay and not sleep, readl_poll_timeout_atomic etc.) from
> iopoll.h
>
>   int err;
>   u32 val;
>
>   err = readl_poll_timeout(pcie->afi + AFI_PCIE_PME, val,
>                            val & (0x1 << pcie->soc->pme_ack_bit[port]),
>                            1, PME_ACK_TIMEOUT);
>   if (err)
>     ...
>
>> +
>> +    if (data)
>> +        dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",
>> +            port->index);
>> +
>
> Typo here, s/receieved/received/
>
> Cheers,
> Mikko
>
>> +    usleep_range(10000, 11000);
>> +
>> +    data = afi_readl(pcie, AFI_PCIE_PME);
>> +    data &= ~(0x1 << get_pme_turnoff_bitmap(port));
>> +    afi_writel(pcie, data, AFI_PCIE_PME);
>> +}
>> +
>>  static int tegra_msi_alloc(struct tegra_msi *chip)
>>  {
>>      int msi;
>> @@ -2828,6 +2901,7 @@ static int tegra_pcie_remove(struct
>> platform_device *pdev)
>>  {
>>      struct tegra_pcie *pcie = platform_get_drvdata(pdev);
>>      struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
>> +    struct tegra_pcie_port *port, *tmp;
>>
>>      if (IS_ENABLED(CONFIG_DEBUG_FS))
>>          tegra_pcie_debugfs_exit(pcie);
>> @@ -2835,6 +2909,8 @@ static int tegra_pcie_remove(struct
>> platform_device *pdev)
>>      pci_remove_root_bus(host->bus);
>>      if (IS_ENABLED(CONFIG_PCI_MSI))
>>          tegra_pcie_disable_msi(pcie);
>> +    list_for_each_entry_safe(port, tmp, &pcie->ports, list)
>> +        tegra_pcie_pme_turnoff(port);
>>      tegra_pcie_disable_ports(pcie);
>>      tegra_pcie_free_resources(pcie);
>>      tegra_pcie_disable_controller(pcie);
>>
> --
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Patch

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index bbc2807bcd4a..b380958a3deb 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -155,6 +155,8 @@ 
 #define  AFI_INTR_EN_FPCI_TIMEOUT	(1 << 7)
 #define  AFI_INTR_EN_PRSNT_SENSE	(1 << 8)
 
+#define AFI_PCIE_PME		0xf0
+
 #define AFI_PCIE_CONFIG					0x0f8
 #define  AFI_PCIE_CONFIG_PCIE_DISABLE(x)		(1 << ((x) + 1))
 #define  AFI_PCIE_CONFIG_PCIE_DISABLE_ALL		0xe
@@ -315,6 +317,7 @@ 
 #define PADS_REFCLK_CFG_DRVI_SHIFT		12 /* 15:12 */
 
 #define LINK_RETRAIN_TIMEOUT 100000
+#define PME_ACK_TIMEOUT 10000
 
 struct tegra_msi {
 	struct msi_controller chip;
@@ -1503,6 +1506,76 @@  static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
 	return 0;
 }
 
+static inline u32 get_pme_turnoff_bitmap(struct tegra_pcie_port *port)
+{
+	struct device *dev = port->pcie->dev;
+	struct device_node *np = dev->of_node;
+	int ret = 0;
+
+	switch (port->index) {
+	case 0:
+		ret = 0;
+	case 1:
+		ret = 8;
+	case 2:
+		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
+			ret = 16;
+		else
+			ret = 12;
+	}
+	return ret;
+}
+
+static inline u32 get_pme_ack_bitmap(struct tegra_pcie_port *port)
+{
+	struct device *dev = port->pcie->dev;
+	struct device_node *np = dev->of_node;
+	int ret = 0;
+
+	switch (port->index) {
+	case 0:
+		ret = 5;
+	case 1:
+		ret = 10;
+	case 2:
+		if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
+			ret = 18;
+		else
+			ret = 14;
+	}
+	return ret;
+}
+
+static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
+{
+	struct tegra_pcie *pcie = port->pcie;
+	ktime_t deadline;
+	unsigned int data;
+
+	data = afi_readl(pcie, AFI_PCIE_PME);
+	data |= (0x1 << get_pme_turnoff_bitmap(port));
+	afi_writel(pcie, data, AFI_PCIE_PME);
+
+	deadline = ktime_add_us(ktime_get(), PME_ACK_TIMEOUT);
+	do {
+		data = afi_readl(pcie, AFI_PCIE_PME);
+		data &= (0x1 << get_pme_ack_bitmap(port));
+		udelay(1);
+		if (ktime_after(ktime_get(), deadline))
+			break;
+	} while (!data);
+
+	if (data)
+		dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",
+			port->index);
+
+	usleep_range(10000, 11000);
+
+	data = afi_readl(pcie, AFI_PCIE_PME);
+	data &= ~(0x1 << get_pme_turnoff_bitmap(port));
+	afi_writel(pcie, data, AFI_PCIE_PME);
+}
+
 static int tegra_msi_alloc(struct tegra_msi *chip)
 {
 	int msi;
@@ -2828,6 +2901,7 @@  static int tegra_pcie_remove(struct platform_device *pdev)
 {
 	struct tegra_pcie *pcie = platform_get_drvdata(pdev);
 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
+	struct tegra_pcie_port *port, *tmp;
 
 	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		tegra_pcie_debugfs_exit(pcie);
@@ -2835,6 +2909,8 @@  static int tegra_pcie_remove(struct platform_device *pdev)
 	pci_remove_root_bus(host->bus);
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_disable_msi(pcie);
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+		tegra_pcie_pme_turnoff(port);
 	tegra_pcie_disable_ports(pcie);
 	tegra_pcie_free_resources(pcie);
 	tegra_pcie_disable_controller(pcie);