850-v5.17-0010-PCI-aardvark-Disable-link-training-when-unbinding-dr.patch

From 759dec2e3dfdbd261c41d2279f04f2351c971a49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Tue, 30 Nov 2021 18:29:12 +0100
Subject: [PATCH] PCI: aardvark: Disable link training when unbinding driver
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Disable link training circuit in driver unbind sequence. We want to
leave link training in the same state as it was before the driver was
probed.

Link: https://lore.kernel.org/r/20211130172913.9727-11-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/pci/controller/pci-aardvark.c | 5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1732,6 +1732,11 @@ static int advk_pcie_remove(struct platf
 	if (pcie->reset_gpio)
 		gpiod_set_value_cansleep(pcie->reset_gpio, 1);
 
+	/* Disable link training */
+	val = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
+	val &= ~LINK_TRAINING_EN;
+	advk_writel(pcie, val, PCIE_CORE_CTRL0_REG);
+
 	/* Disable outbound address windows mapping */
 	for (i = 0; i < OB_WIN_COUNT; i++)
 		advk_pcie_disable_ob_win(pcie, i);