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-rw-r--r--target/linux/mvebu/patches-5.4/016-PCI-aardvark-Train-link-immediately-after-enabling-t.patch60
1 files changed, 60 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-5.4/016-PCI-aardvark-Train-link-immediately-after-enabling-t.patch b/target/linux/mvebu/patches-5.4/016-PCI-aardvark-Train-link-immediately-after-enabling-t.patch
new file mode 100644
index 0000000000..c9e49ac2f1
--- /dev/null
+++ b/target/linux/mvebu/patches-5.4/016-PCI-aardvark-Train-link-immediately-after-enabling-t.patch
@@ -0,0 +1,60 @@
+From 6964494582f56a3882c2c53b0edbfe99eb32b2e1 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
+Date: Thu, 30 Apr 2020 10:06:14 +0200
+Subject: [PATCH] PCI: aardvark: Train link immediately after enabling training
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Adding even 100ms (PCI_PM_D3COLD_WAIT) delay between enabling link
+training and starting link training causes detection issues with some
+buggy cards (such as Compex WLE900VX).
+
+Move the code which enables link training immediately before the one
+which starts link traning.
+
+This fixes detection issues of Compex WLE900VX card on Turris MOX after
+cold boot.
+
+Link: https://lore.kernel.org/r/20200430080625.26070-2-pali@kernel.org
+Fixes: f4c7d053d7f7 ("PCI: aardvark: Wait for endpoint to be ready...")
+Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
+Signed-off-by: Pali Rohár <pali@kernel.org>
+Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+Acked-by: Rob Herring <robh@kernel.org>
+Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
+---
+ drivers/pci/controller/pci-aardvark.c | 15 +++++++++------
+ 1 file changed, 9 insertions(+), 6 deletions(-)
+
+--- a/drivers/pci/controller/pci-aardvark.c
++++ b/drivers/pci/controller/pci-aardvark.c
+@@ -300,11 +300,6 @@ static void advk_pcie_setup_hw(struct ad
+ reg |= LANE_COUNT_1;
+ advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
+
+- /* Enable link training */
+- reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
+- reg |= LINK_TRAINING_EN;
+- advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
+-
+ /* Enable MSI */
+ reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
+ reg |= PCIE_CORE_CTRL2_MSI_ENABLE;
+@@ -346,7 +341,15 @@ static void advk_pcie_setup_hw(struct ad
+ */
+ msleep(PCI_PM_D3COLD_WAIT);
+
+- /* Start link training */
++ /* Enable link training */
++ reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
++ reg |= LINK_TRAINING_EN;
++ advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
++
++ /*
++ * Start link training immediately after enabling it.
++ * This solves problems for some buggy cards.
++ */
+ reg = advk_readl(pcie, PCIE_CORE_LINK_CTRL_STAT_REG);
+ reg |= PCIE_CORE_LINK_TRAINING;
+ advk_writel(pcie, reg, PCIE_CORE_LINK_CTRL_STAT_REG);