[PATCH 4.19 019/247] PCI: qcom: Use PHY_REFCLK_USE_PAD only for ipq8064

[Greg Kroah-Hartman]

From: Ansuel Smith <ansuelsmth@xxxxxxxxx>

commit 2cfef1971aea6119ee27429181d6cb3383031ac2 upstream.

The use of PHY_REFCLK_USE_PAD introduced a regression for apq8064 devices.
It was tested that while apq doesn't require the padding, ipq SoC must use
it or the kernel hangs on boot.

Link: https://lore.kernel.org/r/20201019165555.8269-1-ansuelsmth@xxxxxxxxx
Fixes: de3c4bf64897 ("PCI: qcom: Add support for tx term offset for rev 2.1.0")
Reported-by: Ilia Mirkin <imirkin@xxxxxxxxxxxx>
Signed-off-by: Ilia Mirkin <imirkin@xxxxxxxxxxxx>
Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Stanimir Varbanov <svarbanov@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx	# v4.19+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-qcom.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -371,7 +371,9 @@ static int qcom_pcie_init_2_1_0(struct q
 
 	/* enable external reference clock */
 	val = readl(pcie->parf + PCIE20_PARF_PHY_REFCLK);
-	val &= ~PHY_REFCLK_USE_PAD;
+	/* USE_PAD is required only for ipq806x */
+	if (!of_device_is_compatible(node, "qcom,pcie-apq8064"))
+		val &= ~PHY_REFCLK_USE_PAD;
 	val |= PHY_REFCLK_SSP_EN;
 	writel(val, pcie->parf + PCIE20_PARF_PHY_REFCLK);