[PATCH 5.18 0997/1095] PCI: qcom: Power on PHY before IPQ8074 DBI register accesses

Greg Kroah-Hartman
2022-08-15T23:22:39Z

From: Robert Marko <robimarko@gmail.com>

[ 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@gmail.com
Fixes: a0fd361db8e5 ("PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into common code")
Signed-off-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: stable@vger.kernel.org # v5.11+
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/controller/dwc/pcie-qcom.c | 48 +++++++++++++++-----------
1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index ab04818f6ed9..340542aab8a5 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1036,9 +1036,7 @@ 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]);
@@ -1095,6 +1093,33 @@ 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);

@@ -1122,24 +1147,6 @@ 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)
@@ -1465,6 +1472,7 @@ 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,
};
--
2.35.1