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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 v8 01/14] PCI: tegra194: Fix polling delay for L2 state
Date: Wed, 25 Mar 2026 00:37:42 +0530	[thread overview]
Message-ID: <20260324190755.1094879-2-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20260324190755.1094879-1-mmaddireddy@nvidia.com>

From: Vidya Sagar <vidyas@nvidia.com>

As per PCIe spec r7.0, sec 5.3.3.2.1, after sending PME_Turn_Off message,
Root Port should wait for 1~10 msec for PME_TO_Ack message. Currently,
driver is polling for 10 msec with 1 usec delay which is aggressive.
Use existing macro PCIE_PME_TO_L2_TIMEOUT_US to poll for 10 msec with
1 msec delay. Since this function is used in non-atomic context only,
use non-atomic poll function.

Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
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 V8: None
Changes V6 -> V7: Use PCIE_PME_TO_L2_TIMEOUT_US instead PME_ACK_TIMEOUT
Changes V1 -> V6: None

 drivers/pci/controller/dwc/pcie-tegra194.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 0ddeef70726d..d6c6bd512b51 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -198,8 +198,6 @@
 #define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_MASK	GENMASK(11, 8)
 #define CAP_SPCIE_CAP_OFF_USP_TX_PRESET0_SHIFT	8
 
-#define PME_ACK_TIMEOUT 10000
-
 #define LTSSM_TIMEOUT 50000	/* 50ms */
 
 #define GEN3_GEN4_EQ_PRESET_INIT	5
@@ -1553,9 +1551,10 @@ static int tegra_pcie_try_link_l2(struct tegra_pcie_dw *pcie)
 	val |= APPL_PM_XMT_TURNOFF_STATE;
 	appl_writel(pcie, val, APPL_RADM_STATUS);
 
-	return readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG, val,
-				 val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
-				 1, PME_ACK_TIMEOUT);
+	return readl_poll_timeout(pcie->appl_base + APPL_DEBUG, val,
+				  val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
+				  PCIE_PME_TO_L2_TIMEOUT_US/10,
+				  PCIE_PME_TO_L2_TIMEOUT_US);
 }
 
 static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
-- 
2.34.1


  reply	other threads:[~2026-03-24 19:08 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-24 19:07 [PATCH v8 00/14] Fixes to pcie-tegra194 driver Manikanta Maddireddy
2026-03-24 19:07 ` Manikanta Maddireddy [this message]
2026-03-24 19:07 ` [PATCH v8 02/14] PCI: tegra194: Increase LTSSM poll time on surprise down Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 03/14] PCI: tegra194: Disable LTSSM after transition to detect " Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 04/14] PCI: tegra194: Don't force the device into the D0 state before L2 Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 05/14] PCI: tegra194: Disable PERST IRQ only in Endpoint mode Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 06/14] PCI: tegra194: Use devm_gpiod_get_optional() to parse "nvidia,refclk-select" Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 07/14] PCI: tegra194: Disable direct speed change for Endpoint Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 08/14] PCI: tegra194: Set LTR message request before PCIe link up Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 09/14] PCI: tegra194: Allow system suspend when the Endpoint link is not up Manikanta Maddireddy
2026-04-08 20:59   ` Bjorn Helgaas
2026-04-08 21:03     ` Bjorn Helgaas
2026-04-09  6:59       ` Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 10/14] PCI: tegra194: Free up EP resources during remove() Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 11/14] PCI: tegra194: Use DWC IP core version Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 12/14] PCI: dwc: Apply ECRC workaround to DesignWare 5.00a as well Manikanta Maddireddy
2026-04-08 22:24   ` Bjorn Helgaas
2026-04-09  8:51     ` Manikanta Maddireddy
2026-04-09 18:45       ` Bjorn Helgaas
2026-04-10  6:32         ` Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 13/14] PCI: tegra194: Disable L1.2 capability of Tegra234 EP Manikanta Maddireddy
2026-03-24 19:07 ` [PATCH v8 14/14] PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on Manikanta Maddireddy
2026-04-04 15:10 ` [PATCH v8 00/14] Fixes to pcie-tegra194 driver Manivannan Sadhasivam

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