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[08/12] PCI: tegra: Wait for DLLP to finish before entering L1 or L2

Message ID 1509132569-9398-9-git-send-email-mmaddireddy@nvidia.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Manikanta Maddireddy Oct. 27, 2017, 7:29 p.m. UTC
Set required bit to have LTSSM wait for DLLP to finish before entering L1
or L2. This avoids truncation of PM messages which results in receiver
errors.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
 drivers/pci/host/pci-tegra.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Vidya Sagar Oct. 29, 2017, 9:42 a.m. UTC | #1
On Saturday 28 October 2017 12:59 AM, Manikanta Maddireddy wrote:
> Set required bit to have LTSSM wait for DLLP to finish before entering L1
> or L2. This avoids truncation of PM messages which results in receiver
> errors.
>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> ---
>   drivers/pci/host/pci-tegra.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index b8cac871712b..6028d5f3d5bb 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -217,6 +217,9 @@
>   #define RP_VEND_CTL1	0xf48
>   #define  RP_VEND_CTL1_ERPT	(1 << 13)
>   
> +#define RP_VEND_XP_BIST	0xf4c
> +#define  RP_VEND_XP_BIST_GOTO_L1_L2_AFTER_DLLP_DONE	(1 << 28)
> +
BIT macro is preferred here.
>   #define RP_VEND_CTL2 0x00000fa8
>   #define  RP_VEND_CTL2_PCA_ENABLE (1 << 7)
>   
> @@ -2160,6 +2163,13 @@ static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port)
>   	value |= RP_VEND_XP_OPPORTUNISTIC_ACK;
>   	value |= RP_VEND_XP_OPPORTUNISTIC_UPDATEFC;
>   	writel(value, port->base + RP_VEND_XP);
> +
> +	/* LTSSM will wait for DLLP to finish before entering L1 or L2,
> +	 * to avoid truncation of PM messages which results in receiver errors
> +	 */
> +	value = readl(port->base + RP_VEND_XP_BIST);
> +	value |= RP_VEND_XP_BIST_GOTO_L1_L2_AFTER_DLLP_DONE;
> +	writel(value, port->base + RP_VEND_XP_BIST);
>   }
>   /*
>    * FIXME: If there are no PCIe cards attached, then calling this function
Manikanta Maddireddy Oct. 30, 2017, 3:56 a.m. UTC | #2
On 29-Oct-17 3:12 PM, Vidya Sagar wrote:
> 
> 
> On Saturday 28 October 2017 12:59 AM, Manikanta Maddireddy wrote:
>> Set required bit to have LTSSM wait for DLLP to finish before entering L1
>> or L2. This avoids truncation of PM messages which results in receiver
>> errors.
>>
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> ---
>>   drivers/pci/host/pci-tegra.c | 10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
>> index b8cac871712b..6028d5f3d5bb 100644
>> --- a/drivers/pci/host/pci-tegra.c
>> +++ b/drivers/pci/host/pci-tegra.c
>> @@ -217,6 +217,9 @@
>>   #define RP_VEND_CTL1    0xf48
>>   #define  RP_VEND_CTL1_ERPT    (1 << 13)
>>   +#define RP_VEND_XP_BIST    0xf4c
>> +#define  RP_VEND_XP_BIST_GOTO_L1_L2_AFTER_DLLP_DONE    (1 << 28)
>> +
> BIT macro is preferred here.
Left shift is used everywhere, so to be inline with that I used same format
>>   #define RP_VEND_CTL2 0x00000fa8
>>   #define  RP_VEND_CTL2_PCA_ENABLE (1 << 7)
>>   @@ -2160,6 +2163,13 @@ static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port)
>>       value |= RP_VEND_XP_OPPORTUNISTIC_ACK;
>>       value |= RP_VEND_XP_OPPORTUNISTIC_UPDATEFC;
>>       writel(value, port->base + RP_VEND_XP);
>> +
>> +    /* LTSSM will wait for DLLP to finish before entering L1 or L2,
>> +     * to avoid truncation of PM messages which results in receiver errors
>> +     */
>> +    value = readl(port->base + RP_VEND_XP_BIST);
>> +    value |= RP_VEND_XP_BIST_GOTO_L1_L2_AFTER_DLLP_DONE;
>> +    writel(value, port->base + RP_VEND_XP_BIST);
>>   }
>>   /*
>>    * FIXME: If there are no PCIe cards attached, then calling this function
>
diff mbox

Patch

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index b8cac871712b..6028d5f3d5bb 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -217,6 +217,9 @@ 
 #define RP_VEND_CTL1	0xf48
 #define  RP_VEND_CTL1_ERPT	(1 << 13)
 
+#define RP_VEND_XP_BIST	0xf4c
+#define  RP_VEND_XP_BIST_GOTO_L1_L2_AFTER_DLLP_DONE	(1 << 28)
+
 #define RP_VEND_CTL2 0x00000fa8
 #define  RP_VEND_CTL2_PCA_ENABLE (1 << 7)
 
@@ -2160,6 +2163,13 @@  static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port)
 	value |= RP_VEND_XP_OPPORTUNISTIC_ACK;
 	value |= RP_VEND_XP_OPPORTUNISTIC_UPDATEFC;
 	writel(value, port->base + RP_VEND_XP);
+
+	/* LTSSM will wait for DLLP to finish before entering L1 or L2,
+	 * to avoid truncation of PM messages which results in receiver errors
+	 */
+	value = readl(port->base + RP_VEND_XP_BIST);
+	value |= RP_VEND_XP_BIST_GOTO_L1_L2_AFTER_DLLP_DONE;
+	writel(value, port->base + RP_VEND_XP_BIST);
 }
 /*
  * FIXME: If there are no PCIe cards attached, then calling this function