From: Enric Balletbo i Serra enric.balletbo@collabora.com
[ Upstream commit dc1b5d9aed1794b5a1c6b0da46e372cc09974cbc ]
The required clocks needs to be enabled before the first register access. After commit fe8abf332b8f ("usb: dwc3: support clocks and resets for DWC3 core"), this happens when the dwc3_core_is_valid function is called, but the mentioned commit adds that call in the wrong place, before the clocks are enabled. So, move that call after the clk_bulk_enable() to ensure the clocks are enabled and the reset deasserted.
I detected this while, as experiment, I tried to move the clocks and resets from the glue layer to the DWC3 core on a Samsung Chromebook Plus.
That was not detected before because, in most cases, the glue layer initializes SoC-specific things and then populates the child "snps,dwc3" with those clocks already enabled.
Fixes: b873e2d0ea1ef ("usb: dwc3: Do core validation early on probe") Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/dwc3/core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 4aff1d8dbc4f..6e9e172010fc 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);
@@ -1525,6 +1526,7 @@ static int dwc3_probe(struct platform_device *pdev) 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);