[PATCH] usb: dwc3: move core validatation after clock enable and reset deassert

From: Masahiro Yamada
Date: Mon May 20 2019 - 05:32:04 EST


Since commit b873e2d0ea1e ("usb: dwc3: Do core validation early on
probe"), the DWC3 USB3 does not work for Socionext UniPhier platform.

It moved dwc3_core_is_valid() really early, where no clock is enabled,
no reset is deasserted. Any attempt to register access causes the
system stall on my platform.

Move it after clk_bulk_enable(), and still before dwc3_get_dr_mode().

Fixes: b873e2d0ea1e ("usb: dwc3: Do core validation early on probe")
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

drivers/usb/dwc3/core.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 4aff1d8dbc4f..93b96e6abddb 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1423,11 +1423,6 @@ static int dwc3_probe(struct platform_device *pdev)
dwc->regs = regs;
dwc->regs_size = resource_size(&dwc_res);

- if (!dwc3_core_is_valid(dwc)) {
- dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
- return -ENODEV;
- }
-
dwc3_get_properties(dwc);

dwc->reset = devm_reset_control_get_optional_shared(dev, NULL);
@@ -1460,6 +1455,12 @@ static int dwc3_probe(struct platform_device *pdev)
if (ret)
goto unprepare_clks;

+ if (!dwc3_core_is_valid(dwc)) {
+ dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
+ ret = -ENODEV;
+ goto disable_clks;
+ }
+
platform_set_drvdata(pdev, dwc);
dwc3_cache_hwparams(dwc);

@@ -1524,7 +1525,7 @@ static int dwc3_probe(struct platform_device *pdev)
err1:
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
-
+disable_clks:
clk_bulk_disable(dwc->num_clks, dwc->clks);
unprepare_clks:
clk_bulk_unprepare(dwc->num_clks, dwc->clks);
--
2.17.1