From: Vidya Sagar <vidyas@nvidia.com>
To: <bhelgaas@google.com>, <robh+dt@kernel.org>,
<mark.rutland@arm.com>, <thierry.reding@gmail.com>,
<jonathanh@nvidia.com>, <kishon@ti.com>,
<catalin.marinas@arm.com>, <will.deacon@arm.com>,
<lorenzo.pieralisi@arm.com>, <jingoohan1@gmail.com>,
<gustavo.pimentel@synopsys.com>, <mperttunen@nvidia.com>
Cc: <linux-pci@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>, <kthota@nvidia.com>,
<mmaddireddy@nvidia.com>, <vidyas@nvidia.com>,
<sagar.tv@gmail.com>
Subject: [PATCH V2 09/16] Documentation/devicetree: Add PCIe supports-clkreq property
Date: Fri, 5 Apr 2019 01:24:36 +0530 [thread overview]
Message-ID: <1554407683-31580-10-git-send-email-vidyas@nvidia.com> (raw)
In-Reply-To: <1554407683-31580-1-git-send-email-vidyas@nvidia.com>
Some host controllers need to know the existence of clkreq signal routing to
downstream devices to be able to advertise low power features like ASPM L1
substates. Without clkreq signal routing being present, enabling ASPM L1 sub
states might lead to downstream devices falling off the bus. Hence a new device
tree property 'supports-clkreq' is added to make such host controllers
aware of clkreq signal routing to downstream devices.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
Changes since [v1]:
* This is a new patch in v2 series
Documentation/devicetree/bindings/pci/pci.txt | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
index c77981c5dd18..8ab574704c7a 100644
--- a/Documentation/devicetree/bindings/pci/pci.txt
+++ b/Documentation/devicetree/bindings/pci/pci.txt
@@ -24,3 +24,8 @@ driver implementation may support the following properties:
unsupported link speed, for instance, trying to do training for
unsupported link speed, etc. Must be '4' for gen4, '3' for gen3, '2'
for gen2, and '1' for gen1. Any other values are invalid.
+- supports-clkreq:
+ If present this property specifies that CLKREQ signal routing exists from
+ root port to downstream device and host bridge drivers can do programming
+ which depends on CLKREQ signal existence. For example, programming root port
+ not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal.
--
2.7.4
next prev parent reply other threads:[~2019-04-04 19:56 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 19:54 [PATCH V2 00/16] Add Tegra194 PCIe support Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 01/16] PCI: Add #defines for PCIe spec r4.0 features Vidya Sagar
2019-04-11 10:13 ` Thierry Reding
2019-04-16 13:15 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 02/16] PCI/PME: Export pcie_pme_disable_msi() API Vidya Sagar
2019-04-11 10:16 ` Thierry Reding
2019-04-16 13:30 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 03/16] PCI: Export pcie_bus_config symbol Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 04/16] PCI: dwc: Perform dbi regs write lock towards the end Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 05/16] PCI: dwc: Move config space capability search API Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 06/16] PCI: dwc: Add ext " Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 07/16] dt-bindings: PCI: designware: Add binding for CDM register check Vidya Sagar
2019-04-15 14:54 ` Thierry Reding
2019-04-16 14:29 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 08/16] PCI: dwc: Add support to enable " Vidya Sagar
2019-04-04 19:54 ` Vidya Sagar [this message]
2019-04-04 19:54 ` [PATCH V2 10/16] dt-bindings: PCI: tegra: Add device tree support for T194 Vidya Sagar
2019-04-15 15:08 ` Thierry Reding
2019-04-16 15:33 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 11/16] dt-bindings: PHY: P2U: Add Tegra 194 P2U block Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 12/16] arm64: tegra: Add P2U and PCIe controller nodes to Tegra194 DT Vidya Sagar
2019-04-15 15:15 ` Thierry Reding
2019-04-16 17:48 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 13/16] arm64: tegra: Enable PCIe slots in P2972-0000 board Vidya Sagar
2019-04-15 15:12 ` Thierry Reding
2019-04-16 17:55 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 14/16] phy: tegra: Add PCIe PIPE2UPHY support Vidya Sagar
2019-04-15 15:31 ` Thierry Reding
2019-04-15 15:33 ` Thierry Reding
2019-04-16 18:14 ` Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 15/16] PCI: tegra: Add Tegra194 PCIe support Vidya Sagar
2019-04-04 19:54 ` [PATCH V2 16/16] arm64: Add Tegra194 PCIe driver to defconfig Vidya Sagar
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