diff mbox series

[V2,06/12] PCI: tegra: Enable opportunistic update FC and ACK

Message ID 1509337143-25963-7-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State Superseded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 DL sends pending ACKs and update FC packets when
link is idle instead of waiting for timers to expire which improves PCIe
bandwidth.

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

 drivers/pci/host/pci-tegra.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

Comments

Mikko Perttunen Oct. 30, 2017, 9:58 a.m. UTC | #1
On 30.10.2017 06:18, Manikanta Maddireddy wrote:
> This patch ensures that DL sends pending ACKs and update FC packets when
> link is idle instead of waiting for timers to expire which improves PCIe
> bandwidth.
>
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> ---
> V2:
> * no change in this patch
>
>  drivers/pci/host/pci-tegra.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index 51b7821646eb..bf615c5e6b78 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -209,7 +209,9 @@
>  #define  RP_ECTL_6_R2_RX_EQ_CTRL_H_1C_MASK	0xffffffff
>
>  #define RP_VEND_XP	0x00000f00
> -#define  RP_VEND_XP_DL_UP	(1 << 30)
> +#define  RP_VEND_XP_DL_UP			(1 << 30)
> +#define  RP_VEND_XP_OPPORTUNISTIC_ACK		(1 << 27)
> +#define  RP_VEND_XP_OPPORTUNISTIC_UPDATEFC	(1 << 28)
>
>  #define RP_VEND_CTL1	0xf48
>  #define  RP_VEND_CTL1_ERPT	(1 << 13)
> @@ -2147,6 +2149,16 @@ static void tegra_pcie_enable_rp_features(struct tegra_pcie_port *port)
>  	writel(value, port->base + RP_VEND_CTL1);
>  }
>
> +static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port)
> +{
> +	unsigned long value;
> +
> +	/* Optimal settings to enhance bandwidth */
> +	value = readl(port->base + RP_VEND_XP);
> +	value |= RP_VEND_XP_OPPORTUNISTIC_ACK;
> +	value |= RP_VEND_XP_OPPORTUNISTIC_UPDATEFC;
> +	writel(value, port->base + RP_VEND_XP);
> +}
>  /*
>   * FIXME: If there are no PCIe cards attached, then calling this function
>   * can result in the increase of the bootup time as there are big timeout
> @@ -2215,6 +2227,7 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
>  		if (soc->program_ectl_settings)
>  			tegra_pcie_program_ectl_settings(port);
>  		tegra_pcie_enable_rp_features(port);
> +		tegra_pcie_apply_sw_fixup(port);

As in the AER patch, I think this can be done in-line here. Otherwise 
looks good.

>  	}
>
>  	/* take the PCIe interface module out of reset */
>
diff mbox series

Patch

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 51b7821646eb..bf615c5e6b78 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -209,7 +209,9 @@ 
 #define  RP_ECTL_6_R2_RX_EQ_CTRL_H_1C_MASK	0xffffffff
 
 #define RP_VEND_XP	0x00000f00
-#define  RP_VEND_XP_DL_UP	(1 << 30)
+#define  RP_VEND_XP_DL_UP			(1 << 30)
+#define  RP_VEND_XP_OPPORTUNISTIC_ACK		(1 << 27)
+#define  RP_VEND_XP_OPPORTUNISTIC_UPDATEFC	(1 << 28)
 
 #define RP_VEND_CTL1	0xf48
 #define  RP_VEND_CTL1_ERPT	(1 << 13)
@@ -2147,6 +2149,16 @@  static void tegra_pcie_enable_rp_features(struct tegra_pcie_port *port)
 	writel(value, port->base + RP_VEND_CTL1);
 }
 
+static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port)
+{
+	unsigned long value;
+
+	/* Optimal settings to enhance bandwidth */
+	value = readl(port->base + RP_VEND_XP);
+	value |= RP_VEND_XP_OPPORTUNISTIC_ACK;
+	value |= RP_VEND_XP_OPPORTUNISTIC_UPDATEFC;
+	writel(value, port->base + RP_VEND_XP);
+}
 /*
  * FIXME: If there are no PCIe cards attached, then calling this function
  * can result in the increase of the bootup time as there are big timeout
@@ -2215,6 +2227,7 @@  static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
 		if (soc->program_ectl_settings)
 			tegra_pcie_program_ectl_settings(port);
 		tegra_pcie_enable_rp_features(port);
+		tegra_pcie_apply_sw_fixup(port);
 	}
 
 	/* take the PCIe interface module out of reset */