Patch "PCI: qcom: Power on PHY before IPQ8074 DBI register accesses" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    PCI: qcom: Power on PHY before IPQ8074 DBI register accesses

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pci-qcom-power-on-phy-before-ipq8074-dbi-register-ac.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 5c50abf727e665c6674473b2c2e1016a534cee8c
Author: Robert Marko <robimarko@xxxxxxxxx>
Date:   Thu Jun 23 17:50:03 2022 +0200

    PCI: qcom: Power on PHY before IPQ8074 DBI register accesses
    
    [ Upstream commit a0e43bb9973b06ce5c666f0901e104e2037c1b34 ]
    
    Currently the Gen2 port in IPQ8074 will cause the system to hang as it
    accesses DBI registers in qcom_pcie_init_2_3_3(), and those are only
    accesible after phy_power_on().
    
    Move the DBI read/writes to a new qcom_pcie_post_init_2_3_3(), which is
    executed after phy_power_on().
    
    Link: https://lore.kernel.org/r/20220623155004.688090-1-robimarko@xxxxxxxxx
    Fixes: a0fd361db8e5 ("PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into common code")
    Signed-off-by: Robert Marko <robimarko@xxxxxxxxx>
    Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
    Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
    Cc: stable@xxxxxxxxxxxxxxx      # v5.11+
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 45210c6380b1..4c599699e3c8 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1024,9 +1024,7 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie)
 	struct qcom_pcie_resources_2_3_3 *res = &pcie->res.v2_3_3;
 	struct dw_pcie *pci = pcie->pci;
 	struct device *dev = pci->dev;
-	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
 	int i, ret;
-	u32 val;
 
 	for (i = 0; i < ARRAY_SIZE(res->rst); i++) {
 		ret = reset_control_assert(res->rst[i]);
@@ -1083,6 +1081,33 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie)
 		goto err_clk_aux;
 	}
 
+	return 0;
+
+err_clk_aux:
+	clk_disable_unprepare(res->ahb_clk);
+err_clk_ahb:
+	clk_disable_unprepare(res->axi_s_clk);
+err_clk_axi_s:
+	clk_disable_unprepare(res->axi_m_clk);
+err_clk_axi_m:
+	clk_disable_unprepare(res->iface);
+err_clk_iface:
+	/*
+	 * Not checking for failure, will anyway return
+	 * the original failure in 'ret'.
+	 */
+	for (i = 0; i < ARRAY_SIZE(res->rst); i++)
+		reset_control_assert(res->rst[i]);
+
+	return ret;
+}
+
+static int qcom_pcie_post_init_2_3_3(struct qcom_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
+
 	writel(SLV_ADDR_SPACE_SZ,
 		pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
 
@@ -1110,24 +1135,6 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie)
 		PCI_EXP_DEVCTL2);
 
 	return 0;
-
-err_clk_aux:
-	clk_disable_unprepare(res->ahb_clk);
-err_clk_ahb:
-	clk_disable_unprepare(res->axi_s_clk);
-err_clk_axi_s:
-	clk_disable_unprepare(res->axi_m_clk);
-err_clk_axi_m:
-	clk_disable_unprepare(res->iface);
-err_clk_iface:
-	/*
-	 * Not checking for failure, will anyway return
-	 * the original failure in 'ret'.
-	 */
-	for (i = 0; i < ARRAY_SIZE(res->rst); i++)
-		reset_control_assert(res->rst[i]);
-
-	return ret;
 }
 
 static int qcom_pcie_get_resources_2_7_0(struct qcom_pcie *pcie)
@@ -1423,6 +1430,7 @@ static const struct qcom_pcie_ops ops_2_4_0 = {
 static const struct qcom_pcie_ops ops_2_3_3 = {
 	.get_resources = qcom_pcie_get_resources_2_3_3,
 	.init = qcom_pcie_init_2_3_3,
+	.post_init = qcom_pcie_post_init_2_3_3,
 	.deinit = qcom_pcie_deinit_2_3_3,
 	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
 };