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>,
<jingoohan1@gmail.com>, <vidyas@nvidia.com>, <cassel@kernel.org>,
<18255117159@163.com>
Cc: <linux-pci@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
"Manikanta Maddireddy" <mmaddireddy@nvidia.com>
Subject: [V5,5/9] PCI: tegra194: Enable hardware hot reset mode in Endpoint
Date: Sun, 8 Feb 2026 23:39:32 +0530 [thread overview]
Message-ID: <20260208180936.2026329-6-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20260208180936.2026329-1-mmaddireddy@nvidia.com>
From: Vidya Sagar <vidyas@nvidia.com>
When PCIe link goes down, hardware can retrain the link and try to link up.
To enable this feature, program the APPL_CTRL register with hardware hot
reset with immediate LTSSM enable mode.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
V5:
* None
V4:
* None
V3:
* None
V2:
* None
drivers/pci/controller/dwc/pcie-tegra194.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 110f2adb74d2..f6305a880cad 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1775,6 +1775,8 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
val = appl_readl(pcie, APPL_CTRL);
val |= APPL_CTRL_SYS_PRE_DET_STATE;
val |= APPL_CTRL_HW_HOT_RST_EN;
+ val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK << APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
+ val |= (APPL_CTRL_HW_HOT_RST_MODE_IMDT_RST_LTSSM_EN << APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
appl_writel(pcie, val, APPL_CTRL);
val = appl_readl(pcie, APPL_CFG_MISC);
--
2.34.1
next prev parent reply other threads:[~2026-02-08 18:10 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-08 18:09 [V5,0/9] Enhancements to pcie-tegra194 driver Manikanta Maddireddy
2026-02-08 18:09 ` [V5,1/9] PCI: tegra194: Drive CLKREQ signal low explicitly Manikanta Maddireddy
2026-02-08 18:09 ` [V5,2/9] PCI: tegra194: Calibrate P2U for endpoint mode Manikanta Maddireddy
2026-02-08 18:09 ` [V5,3/9] PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration Manikanta Maddireddy
2026-02-08 18:09 ` [V5,4/9] PCI: tegra194: Enable DMA interrupt Manikanta Maddireddy
2026-02-08 18:09 ` Manikanta Maddireddy [this message]
2026-02-08 18:09 ` [V5,6/9] PCI: tegra194: Disable L1.2 capability of Tegra234 EP Manikanta Maddireddy
2026-02-08 18:09 ` [V5,7/9] dt-bindings: PCI: tegra194: Add monitor clock support Manikanta Maddireddy
2026-02-08 18:09 ` [V5,8/9] PCI: tegra194: Add core " Manikanta Maddireddy
2026-02-08 18:09 ` [V5,9/9] PCI: tegra194: Add ASPM L1 entrance latency config Manikanta Maddireddy
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