From: Manikanta Maddireddy <mmaddireddy@nvidia.com>
To: <bhelgaas@google.com>, <lpieralisi@kernel.org>,
<kwilczynski@kernel.org>, <mani@kernel.org>, <robh@kernel.org>,
<krzk+dt@kernel.org>, <conor+dt@kernel.org>,
<thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
<kishon@kernel.org>, <arnd@arndb.de>,
<gregkh@linuxfoundation.org>, <Frank.Li@nxp.com>,
<den@valinux.co.jp>, <hongxing.zhu@nxp.com>,
<jingoohan1@gmail.com>, <vidyas@nvidia.com>, <cassel@kernel.org>,
<18255117159@163.com>
Cc: <linux-pci@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Manikanta Maddireddy <mmaddireddy@nvidia.com>
Subject: [PATCH v6 9/9] PCI: tegra194: Add ASPM L1 entrance latency config
Date: Tue, 24 Feb 2026 00:15:38 +0530 [thread overview]
Message-ID: <20260223184538.3084753-10-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20260223184538.3084753-1-mmaddireddy@nvidia.com>
For Tegra234, the HW PHY team conducted experiments and determined the
optimal ASPM L1 entrance latency values: 8 us for Root Port mode and
16 us for Endpoint mode. Update the default ASPM L1 entrance latency
configuration accordingly.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
Changes V1 -> V6: None
drivers/pci/controller/dwc/pcie-tegra194.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 82e9ef172de1..1b4fc6a9bed1 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -244,6 +244,8 @@ struct tegra_pcie_dw_of_data {
u32 cdm_chk_int_en_bit;
u32 gen4_preset_vec;
u8 n_fts[2];
+ /* L1 Latency entrance values(Rest/Prod) */
+ u32 aspm_l1_enter_lat;
};
struct tegra_pcie_dw {
@@ -714,6 +716,8 @@ static void init_host_aspm(struct tegra_pcie_dw *pcie)
val = dw_pcie_readl_dbi(pci, PCIE_PORT_AFR);
val &= ~PORT_AFR_L0S_ENTRANCE_LAT_MASK;
val |= (pcie->aspm_l0s_enter_lat << PORT_AFR_L0S_ENTRANCE_LAT_SHIFT);
+ val &= ~PORT_AFR_L1_ENTRANCE_LAT_MASK;
+ val |= (pcie->of_data->aspm_l1_enter_lat << PORT_AFR_L1_ENTRANCE_LAT_SHIFT);
val |= PORT_AFR_ENTER_ASPM;
dw_pcie_writel_dbi(pci, PCIE_PORT_AFR, val);
}
@@ -2471,6 +2475,7 @@ static const struct tegra_pcie_dw_of_data tegra194_pcie_dw_rc_of_data = {
/* Gen4 - 5, 6, 8 and 9 presets enabled */
.gen4_preset_vec = 0x360,
.n_fts = { 52, 52 },
+ .aspm_l1_enter_lat = 3,
};
static const struct tegra_pcie_dw_of_data tegra194_pcie_dw_ep_of_data = {
@@ -2480,6 +2485,7 @@ static const struct tegra_pcie_dw_of_data tegra194_pcie_dw_ep_of_data = {
/* Gen4 - 5, 6, 8 and 9 presets enabled */
.gen4_preset_vec = 0x360,
.n_fts = { 52, 52 },
+ .aspm_l1_enter_lat = 3,
};
static const struct tegra_pcie_dw_of_data tegra234_pcie_dw_rc_of_data = {
@@ -2492,6 +2498,7 @@ static const struct tegra_pcie_dw_of_data tegra234_pcie_dw_rc_of_data = {
/* Gen4 - 6, 8 and 9 presets enabled */
.gen4_preset_vec = 0x340,
.n_fts = { 52, 80 },
+ .aspm_l1_enter_lat = 4,
};
static const struct tegra_pcie_dw_of_data tegra234_pcie_dw_ep_of_data = {
@@ -2504,6 +2511,7 @@ static const struct tegra_pcie_dw_of_data tegra234_pcie_dw_ep_of_data = {
/* Gen4 - 6, 8 and 9 presets enabled */
.gen4_preset_vec = 0x340,
.n_fts = { 52, 80 },
+ .aspm_l1_enter_lat = 5,
};
static const struct of_device_id tegra_pcie_dw_of_match[] = {
--
2.34.1
next prev parent reply other threads:[~2026-02-23 18:47 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-23 18:45 [PATCH v6 0/9] Enhancements to pcie-tegra194 driver Manikanta Maddireddy
2026-02-23 18:45 ` [PATCH v6 1/9] PCI: tegra194: Drive CLKREQ signal low explicitly Manikanta Maddireddy
2026-02-27 12:35 ` Vidya Sagar
2026-03-02 23:34 ` Bjorn Helgaas
2026-03-03 6:51 ` Manikanta Maddireddy
2026-02-23 18:45 ` [PATCH v6 2/9] PCI: tegra194: Calibrate P2U for endpoint mode Manikanta Maddireddy
2026-02-27 12:35 ` Vidya Sagar
2026-02-23 18:45 ` [PATCH v6 3/9] PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration Manikanta Maddireddy
2026-02-27 12:35 ` Vidya Sagar
2026-02-23 18:45 ` [PATCH v6 4/9] PCI: tegra194: Enable DMA interrupt Manikanta Maddireddy
2026-02-27 12:36 ` Vidya Sagar
2026-02-23 18:45 ` [PATCH v6 5/9] PCI: tegra194: Enable hardware hot reset mode in Endpoint Manikanta Maddireddy
2026-02-27 12:36 ` Vidya Sagar
2026-02-23 18:45 ` [PATCH v6 6/9] PCI: tegra194: Disable L1.2 capability of Tegra234 EP Manikanta Maddireddy
2026-02-27 12:36 ` Vidya Sagar
2026-02-23 18:45 ` [PATCH v6 7/9] dt-bindings: PCI: tegra194: Add monitor clock support Manikanta Maddireddy
2026-02-27 12:36 ` Vidya Sagar
2026-02-23 18:45 ` [PATCH v6 8/9] PCI: tegra194: Add core " Manikanta Maddireddy
2026-02-27 12:36 ` Vidya Sagar
2026-02-23 18:45 ` Manikanta Maddireddy [this message]
2026-02-27 12:36 ` [PATCH v6 9/9] PCI: tegra194: Add ASPM L1 entrance latency config Vidya Sagar
2026-02-27 16:59 ` [PATCH v6 0/9] Enhancements to pcie-tegra194 driver Jon Hunter
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