FAILED: patch "[PATCH] phy: freescale: imx8m-pcie: assert phy reset and perst in" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-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]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x aecb63e88c5e5fb9afb782a1577264c76f179af9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025041739-buffoon-panorama-8f27@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From aecb63e88c5e5fb9afb782a1577264c76f179af9 Mon Sep 17 00:00:00 2001
From: Stefan Eichenberger <[email protected]>
Date: Wed, 5 Mar 2025 15:43:16 +0100
Subject: [PATCH] phy: freescale: imx8m-pcie: assert phy reset and perst in
power off

Ensure the PHY reset and perst is asserted during power-off to guarantee it is in a reset state upon repeated power-on calls. This resolves an issue where the PHY may not properly initialize during subsequent power-on cycles. Power-on will deassert the reset at the appropriate time after tuning the PHY parameters.

During suspend/resume cycles, we observed that the PHY PLL failed to
lock during resume when the CPU temperature increased from 65C to 75C.
The observed errors were:
phy phy-32f00000.pcie-phy.3: phy poweron failed --> -110
imx6q-pcie 33800000.pcie: waiting for PHY ready timeout!
imx6q-pcie 33800000.pcie: PM: dpm_run_callback(): genpd_resume_noirq+0x0/0x80 returns -110 imx6q-pcie 33800000.pcie: PM: failed to resume noirq: error -110

This resulted in a complete CPU freeze, which is resolved by ensuring the PHY is in reset during power-on, thus preventing PHY PLL failures.

index 5b505e34ca36..7355d9921b64 100644
@@ -156,6 +156,16 @@ static int imx8_pcie_phy_power_on(struct phy *phy)
 	return ret;
 }
 
+static int imx8_pcie_phy_power_off(struct phy *phy)
+{
+	struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
+
+	reset_control_assert(imx8_phy->reset);
+	reset_control_assert(imx8_phy->perst);
+
+	return 0;
+}
+
 static int imx8_pcie_phy_init(struct phy *phy)
 {
 	struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);

@@ -176,6 +186,7 @@ static const struct phy_ops imx8_pcie_phy_ops = {
 	.init		= imx8_pcie_phy_init,
 	.exit		= imx8_pcie_phy_exit,
 	.power_on	= imx8_pcie_phy_power_on,
+	.power_off	= imx8_pcie_phy_power_off,
 	.owner		= THIS_MODULE,
 };