[PATCH 5.15 115/135] PCI: aardvark: Disable link training when unbinding driver

Greg Kroah-Hartman
2022-05-10T14:16:50Z

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From: Pali Rohár <pali@kernel.org>

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>
---
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
@@ -1725,6 +1725,11 @@ 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);