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 v7 07/13] PCI: tegra194: Set LTR message request before PCIe link up
Date: Tue, 3 Mar 2026 12:24:42 +0530 [thread overview]
Message-ID: <20260303065448.2361488-8-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20260303065448.2361488-1-mmaddireddy@nvidia.com>
From: Vidya Sagar <vidyas@nvidia.com>
LTR message should be sent as soon as the Root Port enables LTR in the
Endpoint. Set snoop & no snoop LTR timing and LTR message request before
PCIe links up. This ensures that LTR message is sent upstream as soon as
LTR is enabled.
Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194")
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
Changes V6 -> V7: Retain FIELD_PREP() usage
Changes V1 -> V6: None
drivers/pci/controller/dwc/pcie-tegra194.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 2da3478f0b5f..b50229df890e 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -485,15 +485,6 @@ static irqreturn_t tegra_pcie_ep_irq_thread(int irq, void *arg)
if (val & PCI_COMMAND_MASTER) {
ktime_t timeout;
- /* 110us for both snoop and no-snoop */
- val = FIELD_PREP(PCI_LTR_VALUE_MASK, 110) |
- FIELD_PREP(PCI_LTR_SCALE_MASK, 2) |
- LTR_MSG_REQ |
- FIELD_PREP(PCI_LTR_NOSNOOP_VALUE, 110) |
- FIELD_PREP(PCI_LTR_NOSNOOP_SCALE, 2) |
- LTR_NOSNOOP_MSG_REQ;
- appl_writel(pcie, val, APPL_LTR_MSG_1);
-
/* Send LTR upstream */
val = appl_readl(pcie, APPL_LTR_MSG_2);
val |= APPL_LTR_MSG_2_LTR_MSG_REQ_STATE;
@@ -1803,6 +1794,15 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
val |= APPL_INTR_EN_L1_0_0_RDLH_LINK_UP_INT_EN;
appl_writel(pcie, val, APPL_INTR_EN_L1_0_0);
+ /* 110us for both snoop and no-snoop */
+ val = FIELD_PREP(PCI_LTR_VALUE_MASK, 110) |
+ FIELD_PREP(PCI_LTR_SCALE_MASK, 2) |
+ LTR_MSG_REQ |
+ FIELD_PREP(PCI_LTR_NOSNOOP_VALUE, 110) |
+ FIELD_PREP(PCI_LTR_NOSNOOP_SCALE, 2) |
+ LTR_NOSNOOP_MSG_REQ;
+ appl_writel(pcie, val, APPL_LTR_MSG_1);
+
reset_control_deassert(pcie->core_rst);
val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
--
2.34.1
next prev parent reply other threads:[~2026-03-03 6:56 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-03 6:54 [PATCH v7 00/13] Fixes to pcie-tegra194 driver Manikanta Maddireddy
2026-03-03 6:54 ` [PATCH v7 01/13] PCI: tegra194: Fix polling delay for L2 state Manikanta Maddireddy
2026-03-03 6:54 ` [PATCH v7 02/13] PCI: tegra194: Refactor LTSSM state polling on surprise down Manikanta Maddireddy
2026-03-05 9:31 ` Manivannan Sadhasivam
2026-03-03 6:54 ` [PATCH v7 03/13] PCI: tegra194: Don't force the device into the D0 state before L2 Manikanta Maddireddy
2026-03-05 9:40 ` Manivannan Sadhasivam
2026-03-15 13:21 ` Manikanta Maddireddy
2026-03-16 1:25 ` Manivannan Sadhasivam
2026-03-03 6:54 ` [PATCH v7 04/13] PCI: tegra194: Disable PERST IRQ only in Endpoint mode Manikanta Maddireddy
2026-03-03 6:54 ` [PATCH v7 05/13] PCI: tegra194: Use devm_gpiod_get_optional() to parse "nvidia,refclk-select" Manikanta Maddireddy
2026-03-03 6:54 ` [PATCH v7 06/13] PCI: tegra194: Disable direct speed change for EP Manikanta Maddireddy
2026-03-05 9:43 ` Manivannan Sadhasivam
2026-03-15 13:44 ` Manikanta Maddireddy
2026-03-16 1:27 ` Manivannan Sadhasivam
2026-03-03 6:54 ` Manikanta Maddireddy [this message]
2026-03-05 10:18 ` [PATCH v7 07/13] PCI: tegra194: Set LTR message request before PCIe link up Manivannan Sadhasivam
2026-03-15 13:49 ` Manikanta Maddireddy
2026-03-16 1:28 ` Manivannan Sadhasivam
2026-03-03 6:54 ` [PATCH v7 08/13] PCI: tegra194: Apply pinctrl settings for both PCIe RP and EP Manikanta Maddireddy
2026-03-05 10:19 ` Manivannan Sadhasivam
2026-03-15 13:54 ` Manikanta Maddireddy
2026-03-16 1:31 ` Manivannan Sadhasivam
2026-03-16 3:41 ` Manikanta Maddireddy
2026-03-16 4:26 ` Manivannan Sadhasivam
2026-03-03 6:54 ` [PATCH v7 09/13] PCI: tegra194: Allow system suspend when the Endpoint link is not up Manikanta Maddireddy
2026-03-05 10:29 ` Manivannan Sadhasivam
2026-03-15 14:10 ` Manikanta Maddireddy
2026-03-16 1:34 ` Manivannan Sadhasivam
2026-03-03 6:54 ` [PATCH v7 10/13] PCI: tegra194: Free up EP resources during remove() Manikanta Maddireddy
2026-03-03 6:54 ` [PATCH v7 11/13] PCI: tegra194: Use HW version number Manikanta Maddireddy
2026-03-05 10:34 ` Manivannan Sadhasivam
2026-03-03 6:54 ` [PATCH v7 12/13] PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on Manikanta Maddireddy
2026-03-03 6:54 ` [PATCH v7 13/13] PCI: tegra194: Free resources during controller deinitialization Manikanta Maddireddy
2026-03-05 10:43 ` Manivannan Sadhasivam
2026-03-15 14:16 ` Manikanta Maddireddy
2026-03-16 1:35 ` Manivannan Sadhasivam
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