diff mbox series

[V2,08/12] PCI: tegra: Wait for DLLP to finish before entering L1 or L2

Message ID 1509337143-25963-9-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State Superseded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
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>
---
V2:
* no change in this patch

 drivers/pci/host/pci-tegra.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Mikko Perttunen Oct. 30, 2017, 10:02 a.m. UTC | #1
On 30.10.2017 06:18, 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>
> ---
> V2:
> * no change in this patch
>
>  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 75b408b32b8b..7f1e34e670d7 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
>

This would also move to the calling function, but

Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
diff mbox series

Patch

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 75b408b32b8b..7f1e34e670d7 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