[PATCH v4 1/2] PCI: qcom: Move IPQ8074 DBI register accesses after phy_power_on()

From: Robert Marko
Date: Fri Jun 24 2022 - 06:44:31 EST


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().

Fixes: a0fd361db8e5 ("PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into common code")
Signed-off-by: Robert Marko <robimarko@xxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
Changes in v4:
* Correct title and description

Changes in v3:
* Make sure it applies onto 5.19-rc3
* Update the commit description to make it clear this only affects the
Gen2 port

Changes in v2:
* Rebase onto next-20220621
---
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 a1f1aca2fb59..24708d5d817d 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1061,9 +1061,7 @@ 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]);
@@ -1120,6 +1118,33 @@ 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);

@@ -1147,24 +1172,6 @@ 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)
@@ -1596,6 +1603,7 @@ 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,
};
--
2.36.1