On Mon, 8 Jun 2015, Vivek Gautam wrote:
> Facilitate getting required 3.3V and 1.0V VDD supply for
> EHCI controller on Exynos.
>
> For example, patches for regulators' nodes:
> c8c253f ARM: dts: Add regulator entries to smdk5420
> 275dcd2 ARM: dts: add max77686 pmic node for smdk5250,
> enable only minimum number of regulators on smdk5250.
>
> So ensuring now that the controller driver requests the necessary
> VDD regulators (if available, unless there are direct VDD rails),
> and enable them so as to make them working on exynos systems.
>
> Signed-off-by: Vivek Gautam <gautam.vi...@samsung.com>
Something about this looks a little fishy...
> @@ -170,7 +173,27 @@ static int exynos_ehci_probe(struct platform_device
> *pdev)
>
> err = exynos_ehci_get_phy(&pdev->dev, exynos_ehci);
> if (err)
> - goto fail_clk;
> + goto fail_regulator1;
> +
> + exynos_ehci->vdd33 = devm_regulator_get_optional(&pdev->dev, "vdd33");
Just before this region of code, there is:
if (of_device_is_compatible(pdev->dev.of_node,
"samsung,exynos5440-ehci"))
goto skip_phy;
If that "goto" is taken, exynos_ehci->vdd33 and ->vdd10 will be NULL,
not an ERR_PTR code.
> + if (!IS_ERR(exynos_ehci->vdd33)) {
> + err = regulator_enable(exynos_ehci->vdd33);
> + if (err) {
> + dev_err(&pdev->dev,
> + "Failed to enable 3.3V Vdd supply\n");
> + goto fail_regulator1;
> + }
> + }
> +
> + exynos_ehci->vdd10 = devm_regulator_get_optional(&pdev->dev, "vdd10");
> + if (!IS_ERR(exynos_ehci->vdd10)) {
> + err = regulator_enable(exynos_ehci->vdd10);
> + if (err) {
> + dev_err(&pdev->dev,
> + "Failed to enable 1.0V Vdd supply\n");
> + goto fail_regulator2;
> + }
> + }
>
> skip_phy:
>
> @@ -231,6 +254,12 @@ fail_add_hcd:
> fail_io:
> clk_disable_unprepare(exynos_ehci->clk);
> fail_clk:
> + if (!IS_ERR(exynos_ehci->vdd10))
> + regulator_disable(exynos_ehci->vdd10);
> +fail_regulator2:
> + if (!IS_ERR(exynos_ehci->vdd33))
> + regulator_disable(exynos_ehci->vdd33);
Which means these regulator_disable() calls will crash when they
dereference a NULL pointer.
I think it would be simpler in the end to let a NULL pointer mean the
regulator isn't present. If devm_regulator_get_optional() returns an
error, convert it to NULL (or don't do the assignment to
exynos_ehci->vdd?? in the first place).
The same criticism applies to the other patch in this series.
Alan Stern
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