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From: Manikanta Maddireddy <mmaddireddy@nvidia.com>
To: <thierry.reding@gmail.com>, <bhelgaas@google.com>,
	<robh+dt@kernel.org>, <mark.rutland@arm.com>,
	<jonathanh@nvidia.com>, <lorenzo.pieralisi@arm.com>,
	<vidyas@nvidia.com>
Cc: <linux-tegra@vger.kernel.org>, <linux-pci@vger.kernel.org>,
	<devicetree@vger.kernel.org>,
	Manikanta Maddireddy <mmaddireddy@nvidia.com>
Subject: [PATCH V4 10/28] PCI: tegra: Disable AFI dynamic clock gating
Date: Thu, 16 May 2019 11:22:49 +0530
Message-ID: <20190516055307.25737-11-mmaddireddy@nvidia.com> (raw)
In-Reply-To: <20190516055307.25737-1-mmaddireddy@nvidia.com>

Outstanding write counter in AFI is used to generate idle signal to
dynamically gate the AFI clock. When there are 32 outstanding writes
from AFI to memory, the outstanding write counter overflows and
indicates that there are "0" outstanding write transactions.

When memory controller is under heavy load, write completions to AFI
gets delayed and AFI write counter overflows. This causes AFI clock gating
even when there are outstanding transactions towards memory controller
resulting in system hang.

Disable dynamic clock gating of AFI clock to avoid system hang.

CLKEN_OVERRIDE bit is not defined in Tegra20 and Tegra30, however
programming this bit doesn't cause any side effects. Program this
bit for all Tegra SoCs to avoid conditional check.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
---
V4: No change

V3: No change

V2: No change

 drivers/pci/controller/pci-tegra.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index b1e2e398b4e8..17c6d858ddc6 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -95,7 +95,8 @@
 #define AFI_MSI_EN_VEC7		0xa8
 
 #define AFI_CONFIGURATION		0xac
-#define  AFI_CONFIGURATION_EN_FPCI	(1 << 0)
+#define  AFI_CONFIGURATION_EN_FPCI		(1 << 0)
+#define  AFI_CONFIGURATION_CLKEN_OVERRIDE	(1 << 31)
 
 #define AFI_FPCI_ERROR_MASKS	0xb0
 
@@ -1065,9 +1066,10 @@ static void tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 		afi_writel(pcie, value, AFI_FUSE);
 	}
 
-	/* finally enable PCIe */
+	/* Disable AFI dynamic clock gating and enable PCIe */
 	value = afi_readl(pcie, AFI_CONFIGURATION);
 	value |= AFI_CONFIGURATION_EN_FPCI;
+	value |= AFI_CONFIGURATION_CLKEN_OVERRIDE;
 	afi_writel(pcie, value, AFI_CONFIGURATION);
 
 	value = AFI_INTR_EN_INI_SLVERR | AFI_INTR_EN_INI_DECERR |
-- 
2.17.1


  parent reply index

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-16  5:52 [PATCH V4 00/28] Enable Tegra PCIe root port features Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 01/28] soc/tegra: pmc: Export tegra_powergate_power_on() Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 02/28] PCI: tegra: Handle failure cases in tegra_pcie_power_on() Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 03/28] PCI: tegra: Rearrange Tegra PCIe driver functions Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 04/28] PCI: tegra: Mask AFI_INTR in runtime suspend Manikanta Maddireddy
2019-06-04 13:08   ` Thierry Reding
2019-05-16  5:52 ` [PATCH V4 05/28] PCI: tegra: Fix PCIe host power up sequence Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 06/28] PCI: tegra: Add PCIe Gen2 link speed support Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 07/28] PCI: tegra: Advertise PCIe Advanced Error Reporting (AER) capability Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 08/28] PCI: tegra: Program UPHY electrical settings for Tegra210 Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 09/28] PCI: tegra: Enable opportunistic UpdateFC and ACK Manikanta Maddireddy
2019-05-16  5:52 ` Manikanta Maddireddy [this message]
2019-05-16  5:52 ` [PATCH V4 11/28] PCI: tegra: Process pending DLL transactions before entering L1 or L2 Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 12/28] PCI: tegra: Enable PCIe xclk clock clamping Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 13/28] PCI: tegra: Increase the deskew retry time Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 14/28] PCI: tegra: Add SW fixup for RAW violations Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 15/28] PCI: tegra: Update flow control timer frequency in Tegra210 Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 16/28] PCI: tegra: Set target speed as Gen1 before starting LTSSM Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 17/28] PCI: tegra: Fix PLLE power down issue due to CLKREQ# signal Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 18/28] PCI: tegra: Program AFI_CACHE* registers only for Tegra20 Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 19/28] PCI: tegra: Change PRSNT_SENSE IRQ log to debug Manikanta Maddireddy
2019-05-16  5:52 ` [PATCH V4 20/28] PCI: tegra: Use legacy IRQ for port service drivers Manikanta Maddireddy
2019-05-20 20:37   ` Bjorn Helgaas
2019-05-21  9:07     ` Manikanta Maddireddy
2019-05-16  5:53 ` [PATCH V4 21/28] PCI: tegra: Add AFI_PEX2_CTRL reg offset as part of soc struct Manikanta Maddireddy
2019-05-16  5:53 ` [PATCH V4 22/28] PCI: tegra: Access endpoint config only if PCIe link is up Manikanta Maddireddy
2019-06-04 13:14   ` Thierry Reding
2019-06-04 14:10     ` Manikanta Maddireddy
2019-06-10  4:38       ` Manikanta Maddireddy
2019-06-13 14:39         ` Lorenzo Pieralisi
2019-06-13 15:42           ` Thierry Reding
2019-06-17 10:01             ` Manikanta Maddireddy
2019-06-17 11:47               ` Thierry Reding
2019-06-17 19:30                 ` Bjorn Helgaas
2019-06-18  5:36                   ` Manikanta Maddireddy
2019-06-18 10:49                     ` Thierry Reding
2019-06-18 12:32                       ` Johannes Berg
2019-06-18 13:40                         ` Thierry Reding
2019-06-18 14:48                           ` Johannes Berg
2019-06-19 13:38                         ` Bjorn Helgaas
2019-06-19 13:40                           ` Johannes Berg
2019-05-16  5:53 ` [PATCH V4 23/28] dt-bindings: pci: tegra: Document PCIe DPD pinctrl optional prop Manikanta Maddireddy
2019-05-16  5:53 ` [PATCH V4 24/28] arm64: tegra: Add PEX DPD states as pinctrl properties Manikanta Maddireddy
2019-05-16  5:53 ` [PATCH V4 25/28] PCI: tegra: Put PEX CLK & BIAS pads in DPD mode Manikanta Maddireddy
2019-05-16  5:53 ` [PATCH V4 26/28] PCI: Add DT binding for "reset-gpios" property Manikanta Maddireddy
2019-06-17 11:30   ` Thierry Reding
2019-06-17 11:38     ` Manikanta Maddireddy
2019-06-17 11:48       ` Thierry Reding
2019-05-16  5:53 ` [PATCH V4 27/28] PCI: tegra: Add support for GPIO based PERST# Manikanta Maddireddy
2019-06-04 13:22   ` Thierry Reding
2019-06-13 15:24     ` Lorenzo Pieralisi
2019-06-14 10:37       ` Manikanta Maddireddy
2019-06-14 14:32         ` Lorenzo Pieralisi
2019-06-14 14:38           ` Manikanta Maddireddy
2019-06-14 14:50             ` Lorenzo Pieralisi
2019-06-14 14:56               ` Manikanta Maddireddy
2019-06-14 15:23               ` Thierry Reding
2019-06-14 15:59                 ` Lorenzo Pieralisi
2019-06-14 16:30                   ` Manikanta Maddireddy
2019-06-14 16:53                     ` Lorenzo Pieralisi
2019-06-14 17:23                       ` Manikanta Maddireddy
2019-06-17  9:48                         ` Lorenzo Pieralisi
2019-06-17 10:27                           ` Manikanta Maddireddy
2019-06-17 10:39                             ` Lorenzo Pieralisi
2019-06-17 11:29                         ` Thierry Reding
2019-06-17 11:26                       ` Thierry Reding
2019-05-16  5:53 ` [PATCH V4 28/28] PCI: tegra: Change link retry log level to debug Manikanta Maddireddy
2019-06-04 13:22   ` Thierry Reding
2019-05-16 13:12 ` [PATCH V4 00/28] Enable Tegra PCIe root port features Bjorn Helgaas
2019-05-17  8:38   ` Manikanta Maddireddy
2019-06-10  4:45 ` Manikanta Maddireddy
2019-06-10 17:33   ` Lorenzo Pieralisi

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