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FAILED: patch "[PATCH] PCI: qcom: Don't deassert reset GPIO during probe" failed to apply to 4.19-stable tree

PATCH [email protected] 1 participant 1 message Mar 20, 2019

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The patch below does not apply to the 4.19-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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 02b485e31d98265189b91f3e69c43df2ed50610c Mon Sep 17 00:00:00 2001
From: Bjorn Andersson <[email protected]>
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")
[[email protected]: updated commit log]
drivers/pci/controller/dwc/pcie-qcom.c +1 -1
index d185ea5fe996..a7f703556790 100644
@@ -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;