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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 V4 1/6] PCI: tegra: Fix ASPM-L1SS advertisement disable code
Date:   Mon, 9 Nov 2020 22:49:32 +0530
Message-ID: <20201109171937.28326-2-vidyas@nvidia.com>
In-Reply-To: <20201109171937.28326-1-vidyas@nvidia.com>
References: <20201109171937.28326-1-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>
---
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 aa511ec0d800..b172b1d49713 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -896,6 +896,12 @@ 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);
@@ -1400,12 +1406,6 @@ static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie,
 	pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
 						      PCI_CAP_ID_EXP);
 
-	/* Disable ASPM-L1SS advertisement as there is no CLKREQ routing */
-	if (!pcie->supports_clkreq) {
-		disable_aspm_l11(pcie);
-		disable_aspm_l12(pcie);
-	}
-
 	return ret;
 
 fail_phy:
-- 
2.17.1