The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 02b485e31d98265189b91f3e69c43df2ed50610c Mon Sep 17 00:00:00 2001
From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Date: Fri, 25 Jan 2019 15:26:16 -0800
Subject: [PATCH] PCI: qcom: Don't deassert reset GPIO during probe
Acquiring the reset GPIO low means that reset is being deasserted, this
is followed almost immediately with qcom_pcie_host_init() asserting it,
initializing it and then finally deasserting it again, for the link to
come up.
Some PCIe devices requires a minimum time between the initial deassert
and subsequent reset cycles. In a platform that boots with the reset
GPIO asserted this requirement is being violated by this deassert/assert
pulse.
Acquire the reset GPIO high to prevent this situation by matching the
state to the subsequent asserted state.
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
[lorenzo.pieralisi@xxxxxxx: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Acked-by: Stanimir Varbanov <svarbanov@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index d185ea5fe996..a7f703556790 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1228,7 +1228,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
pcie->ops = of_device_get_match_data(dev);
- pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_LOW);
+ pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
if (IS_ERR(pcie->reset)) {
ret = PTR_ERR(pcie->reset);
goto err_pm_runtime_put;
