Re: [PATCH] usb: dwc3: move core validation to be after clks enable

[Sriharsha Allenki]

Hi Jun Li,

On 5/8/2019 9:54 AM, Jun Li wrote:
From: Jun Li <jun...@nxp.com>
Register access in core validation may hang before the bulk
clks are enabled.

Fixes: b873e2d0ea1e ("usb: dwc3: Do core validation early on probe")
Signed-off-by: Jun Li <jun...@nxp.com>
---
  drivers/usb/dwc3/core.c | 12 ++++++------
  1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 4aff1d8..0e49ff3 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 +1455,11 @@ 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");

Please update "ret" here with -ENODEV, else the probe call will return 
success (ret is 0).

+               goto disable_clks;
+       }
+
        platform_set_drvdata(pdev, dwc);
        dwc3_cache_hwparams(dwc);
  
@@ -1524,7 +1524,7 @@ 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);

Regards,

Sriharsha