FAILED: patch "[PATCH] PCI: imx6: Fix IMX6SX_GPR12_PCIE_TEST_POWERDOWN handling" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-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@vger.kernel.org>.

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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x aad953fb4eed0df5486cd54ccad80ac197678e01
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071350-dealmaker-sliding-cb76@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From aad953fb4eed0df5486cd54ccad80ac197678e01 Mon Sep 17 00:00:00 2001
From: Richard Zhu <hongxing.zhu@nxp.com>
Date: Thu, 19 Mar 2026 17:08:44 +0800
Subject: [PATCH] PCI: imx6: Fix IMX6SX_GPR12_PCIE_TEST_POWERDOWN handling

The IMX6SX_GPR12_PCIE_TEST_POWERDOWN bit does not control the PCIe
reference clock on i.MX6SX. Instead, it is part of i.MX6SX PCIe core
reset sequence.

Move the IMX6SX_GPR12_PCIE_TEST_POWERDOWN assertion/deassertion into
the core reset functions to properly reflect its purpose. Remove the
.enable_ref_clk() callback for i.MX6SX since it was incorrectly
manipulating this bit.

Fixes: e3c06cd063d6 ("PCI: imx6: Add initial imx6sx support")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260319090844.444987-1-hongxing.zhu@nxp.com

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index e35044cc5218..1034ac5c5f5c 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -665,14 +665,6 @@ static int imx_pcie_attach_pd(struct device *dev)
 	return 0;
 }
 
-static int imx6sx_pcie_enable_ref_clk(struct imx_pcie *imx_pcie, bool enable)
-{
-	regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
-			   IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
-			   enable ? 0 : IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
-	return 0;
-}
-
 static int imx6q_pcie_enable_ref_clk(struct imx_pcie *imx_pcie, bool enable)
 {
 	if (enable) {
@@ -786,6 +778,9 @@ static int imx6sx_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
 	if (assert)
 		regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
+	else
+		regmap_clear_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				  IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
 
 	/* Force PCIe PHY reset */
 	regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR5, IMX6SX_GPR5_PCIE_BTNRST_RESET,
@@ -1877,7 +1872,6 @@ static const struct imx_pcie_drvdata drvdata[] = {
 		.mode_off[0] = IOMUXC_GPR12,
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
 		.init_phy = imx6sx_pcie_init_phy,
-		.enable_ref_clk = imx6sx_pcie_enable_ref_clk,
 		.core_reset = imx6sx_pcie_core_reset,
 		.ops = &imx_pcie_host_ops,
 	},