Linux PCI subsystem development
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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 06/13] PCI: tegra194: Disable direct speed change for EP
Date: Tue, 24 Feb 2026 00:11:44 +0530	[thread overview]
Message-ID: <20260223184151.3083221-7-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20260223184151.3083221-1-mmaddireddy@nvidia.com>

From: Vidya Sagar <vidyas@nvidia.com>

Disable direct speed change for the endpoint to prevent it from initiating
the speed change post physical layer link up at gen1. This leaves the speed
change ownership with the host.

Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
Changes V1 -> V6: None

 drivers/pci/controller/dwc/pcie-tegra194.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 8f69c5c5a099..a6868b77e3b7 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1807,6 +1807,10 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 
 	reset_control_deassert(pcie->core_rst);
 
+	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+	val &= ~PORT_LOGIC_SPEED_CHANGE;
+	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
+
 	if (pcie->update_fc_fixup) {
 		val = dw_pcie_readl_dbi(pci, CFG_TIMER_CTRL_MAX_FUNC_NUM_OFF);
 		val |= 0x1 << CFG_TIMER_CTRL_ACK_NAK_SHIFT;
-- 
2.34.1


  parent reply	other threads:[~2026-02-23 18:43 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-23 18:41 [PATCH v6 00/13] Fixes to pcie-tegra194 driver Manikanta Maddireddy
2026-02-23 18:41 ` [PATCH v6 01/13] PCI: tegra194: Fix polling delay for L2 state Manikanta Maddireddy
2026-02-27 12:32   ` Vidya Sagar
2026-03-02 23:17   ` Bjorn Helgaas
2026-02-23 18:41 ` [PATCH v6 02/13] PCI: tegra194: Refactor LTSSM state polling on surprise down Manikanta Maddireddy
2026-02-27 12:32   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 03/13] PCI: tegra194: Don't force the device into the D0 state before L2 Manikanta Maddireddy
2026-02-27 12:33   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 04/13] PCI: tegra194: Disable PERST IRQ only in Endpoint mode Manikanta Maddireddy
2026-02-27 12:33   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 05/13] PCI: tegra194: Use devm_gpiod_get_optional() to parse "nvidia,refclk-select" Manikanta Maddireddy
2026-02-27 12:33   ` Vidya Sagar
2026-02-23 18:41 ` Manikanta Maddireddy [this message]
2026-02-27 12:33   ` [PATCH v6 06/13] PCI: tegra194: Disable direct speed change for EP Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 07/13] PCI: tegra194: Set LTR message request before PCIe link up Manikanta Maddireddy
2026-02-27 12:33   ` Vidya Sagar
2026-03-02 23:27   ` Bjorn Helgaas
2026-02-23 18:41 ` [PATCH v6 08/13] PCI: tegra194: Apply pinctrl settings for both PCIe RP and EP Manikanta Maddireddy
2026-02-27 12:34   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 09/13] PCI: tegra194: Allow system suspend when the Endpoint link is not up Manikanta Maddireddy
2026-02-27 12:34   ` Vidya Sagar
2026-03-02 23:30   ` Bjorn Helgaas
2026-02-23 18:41 ` [PATCH v6 10/13] PCI: tegra194: Free up EP resources during remove() Manikanta Maddireddy
2026-02-27 12:34   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 11/13] PCI: tegra194: Use HW version number Manikanta Maddireddy
2026-02-27 12:34   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 12/13] PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on Manikanta Maddireddy
2026-02-27 12:34   ` Vidya Sagar
2026-02-23 18:41 ` [PATCH v6 13/13] PCI: tegra194: Free resources during controller deinitialization Manikanta Maddireddy
2026-02-27 12:34   ` Vidya Sagar
2026-02-27 16:59 ` [PATCH v6 00/13] Fixes to pcie-tegra194 driver Jon Hunter

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