PCI: aardvark: Disable link training when unbinding driver

BugLink: https://bugs.launchpad.net/bugs/1978240
commit 759dec2e3dfdbd261c41d2279f04f2351c971a49 upstream.

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>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 78bc57d579262ac29e826d065db859b74b3a6811..3f6919564434be33506903d17e04906aa19288d2 100644 (file)
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1725,6 +1725,11 @@ static int advk_pcie_remove(struct platform_device *pdev)
        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);