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From:   Vidya Sagar <vidyas@nvidia.com>
To:     <lorenzo.pieralisi@arm.com>, <robh+dt@kernel.org>,
        <bhelgaas@google.com>, <thierry.reding@gmail.com>,
        <jonathanh@nvidia.com>, <amanharitsh123@gmail.com>,
        <dinghao.liu@zju.edu.cn>, <kw@linux.com>
CC:     <linux-pci@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <kthota@nvidia.com>,
        <mmaddireddy@nvidia.com>, <vidyas@nvidia.com>, <sagar.tv@gmail.com>
Subject: [PATCH V5 1/5] PCI: tegra: Fix ASPM-L1SS advertisement disable code
Date:   Thu, 3 Dec 2020 19:04:47 +0530
Message-ID: <20201203133451.17716-2-vidyas@nvidia.com>
In-Reply-To: <20201203133451.17716-1-vidyas@nvidia.com>
References: <20201203133451.17716-1-vidyas@nvidia.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

If the absence of CLKREQ# signal is indicated by the absence of
"supports-clkreq" in the device-tree node, current driver is disabling
the advertisement of ASPM-L1 Sub-States *before* the ASPM-L1 Sub-States
offset is correctly initialized. Since default value of the ASPM-L1SS
offset is zero, this is causing the Vendor-ID wrongly programmed to 0x10d2
instead of Nvidia's 0x10de thereby the quirks applicable for Tegra194 are
not being applied. This patch fixes this issue by refactoring the
code that disables the ASPM-L1SS advertisement.

Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V5:
* Rebased on top of the tree code

V4:
* None

V3:
* None

V2:
* None

 drivers/pci/controller/dwc/pcie-tegra194.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 648e731bccfa..4c966e9adb2b 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -863,12 +863,6 @@ static void tegra_pcie_prepare_host(struct pcie_port *pp)
 		pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
 							      PCI_CAP_ID_EXP);
 
-	/* Disable ASPM-L1SS advertisement if there is no CLKREQ routing */
-	if (!pcie->supports_clkreq) {
-		disable_aspm_l11(pcie);
-		disable_aspm_l12(pcie);
-	}
-
 	val = dw_pcie_readl_dbi(pci, PCI_IO_BASE);
 	val &= ~(IO_BASE_IO_DECODE | IO_BASE_IO_DECODE_BIT8);
 	dw_pcie_writel_dbi(pci, PCI_IO_BASE, val);
@@ -897,6 +891,12 @@ static void tegra_pcie_prepare_host(struct pcie_port *pp)
 
 	init_host_aspm(pcie);
 
+	/* Disable ASPM-L1SS advertisement if there is no CLKREQ routing */
+	if (!pcie->supports_clkreq) {
+		disable_aspm_l11(pcie);
+		disable_aspm_l12(pcie);
+	}
+
 	val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
 	val &= ~GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL;
 	dw_pcie_writel_dbi(pci, GEN3_RELATED_OFF, val);
-- 
2.17.1