diff mbox series

[V2,01/12] PCI: tegra: Start LTSSM after programming root port

Message ID 1509337143-25963-2-git-send-email-mmaddireddy@nvidia.com
State Superseded
Headers show
Series Enable Tegra root port features and apply SW fixups | expand

Commit Message

Manikanta Maddireddy Oct. 30, 2017, 4:18 a.m. UTC
This patch ensures that LTSSM is started (by deasserting pcie_xrst) only
after all the required root port register programming is completed.

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

 drivers/pci/host/pci-tegra.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Mikko Perttunen Oct. 30, 2017, 9:08 a.m. UTC | #1
On 30.10.2017 06:18, Manikanta Maddireddy wrote:
> This patch ensures that LTSSM is started (by deasserting pcie_xrst) only
> after all the required root port register programming is completed.
>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> ---
> V2:
> * no change in this patch
>
>  drivers/pci/host/pci-tegra.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index 96e8038c3019..b41c60c7414c 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -1024,9 +1024,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
>  		}
>  	}
>
> -	/* take the PCIe interface module out of reset */
> -	reset_control_deassert(pcie->pcie_xrst);
> -
>  	/* finally enable PCIe */
>  	value = afi_readl(pcie, AFI_CONFIGURATION);
>  	value |= AFI_CONFIGURATION_EN_FPCI;
> @@ -1065,7 +1062,6 @@ static void tegra_pcie_power_off(struct tegra_pcie *pcie)
>  			dev_err(dev, "failed to power off PHY(s): %d\n", err);
>  	}
>
> -	reset_control_assert(pcie->pcie_xrst);

Why is this change being made? Is there a reason we cannot leave this 
reset asserted when the controller is powered off?

>  	reset_control_assert(pcie->afi_rst);
>  	reset_control_assert(pcie->pex_rst);
>
> @@ -2116,7 +2112,12 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
>  			 port->index, port->lanes);
>
>  		tegra_pcie_port_enable(port);
> +	}
>
> +	/* take the PCIe interface module out of reset */
> +	reset_control_deassert(pcie->pcie_xrst);
> +
> +	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
>  		if (tegra_pcie_port_check_link(port))
>  			continue;
>
>
Manikanta Maddireddy Oct. 30, 2017, 10:36 a.m. UTC | #2
On 30-Oct-17 2:38 PM, Mikko Perttunen wrote:
> On 30.10.2017 06:18, Manikanta Maddireddy wrote:
>> This patch ensures that LTSSM is started (by deasserting pcie_xrst) only
>> after all the required root port register programming is completed.
>>
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> ---
>> V2:
>> * no change in this patch
>>
>>  drivers/pci/host/pci-tegra.c | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
>> index 96e8038c3019..b41c60c7414c 100644
>> --- a/drivers/pci/host/pci-tegra.c
>> +++ b/drivers/pci/host/pci-tegra.c
>> @@ -1024,9 +1024,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
>>          }
>>      }
>>
>> -    /* take the PCIe interface module out of reset */
>> -    reset_control_deassert(pcie->pcie_xrst);
>> -
>>      /* finally enable PCIe */
>>      value = afi_readl(pcie, AFI_CONFIGURATION);
>>      value |= AFI_CONFIGURATION_EN_FPCI;
>> @@ -1065,7 +1062,6 @@ static void tegra_pcie_power_off(struct tegra_pcie *pcie)
>>              dev_err(dev, "failed to power off PHY(s): %d\n", err);
>>      }
>>
>> -    reset_control_assert(pcie->pcie_xrst);
> 
> Why is this change being made? Is there a reason we cannot leave this reset asserted when the controller is powered off?
In this change I moved deassert pcie_xrst to tegra_pcie_enable_ports. tegra_pcie_power_off() will not come into picture after deasserting pcie xrst.
So this asserting pcie xrst redundant now.
> 
>>      reset_control_assert(pcie->afi_rst);
>>      reset_control_assert(pcie->pex_rst);
>>
>> @@ -2116,7 +2112,12 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
>>               port->index, port->lanes);
>>
>>          tegra_pcie_port_enable(port);
>> +    }
>>
>> +    /* take the PCIe interface module out of reset */
>> +    reset_control_deassert(pcie->pcie_xrst);
>> +
>> +    list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
>>          if (tegra_pcie_port_check_link(port))
>>              continue;
>>
>>
diff mbox series

Patch

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 96e8038c3019..b41c60c7414c 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -1024,9 +1024,6 @@  static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 		}
 	}
 
-	/* take the PCIe interface module out of reset */
-	reset_control_deassert(pcie->pcie_xrst);
-
 	/* finally enable PCIe */
 	value = afi_readl(pcie, AFI_CONFIGURATION);
 	value |= AFI_CONFIGURATION_EN_FPCI;
@@ -1065,7 +1062,6 @@  static void tegra_pcie_power_off(struct tegra_pcie *pcie)
 			dev_err(dev, "failed to power off PHY(s): %d\n", err);
 	}
 
-	reset_control_assert(pcie->pcie_xrst);
 	reset_control_assert(pcie->afi_rst);
 	reset_control_assert(pcie->pex_rst);
 
@@ -2116,7 +2112,12 @@  static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
 			 port->index, port->lanes);
 
 		tegra_pcie_port_enable(port);
+	}
 
+	/* take the PCIe interface module out of reset */
+	reset_control_deassert(pcie->pcie_xrst);
+
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
 		if (tegra_pcie_port_check_link(port))
 			continue;