On Tue, Jan 14, 2025, Kyle Tso wrote:
> Currently, DWC3 driver attempts to acquire the USB power supply only
> once during the probe. If the USB power supply is not ready at that
> time, the driver simply ignores the failure and continues the probe,
> leading to permanent non-functioning of the gadget vbus_draw callback.
>
> Address this problem by delaying the dwc3 driver initialization until
> the USB power supply is registered.
>
> Fixes: 6f0764b5adea ("usb: dwc3: add a power supply for current control")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Kyle Tso <kyletso@xxxxxxxxxx>
> ---
> Note: This is a follow-up of https://urldefense.com/v3/__https://lore.kernel.org/all/20240804084612.2561230-1-kyletso@xxxxxxxxxx/__;!!A4F2R9G_pg!ZTwcKSid-i7kN4_N622H1QDeC3jzi0uCKRqjzrTNStFGr8guMe3xY0EF30CnGGPyBK25ZCGgUc_Wg3koxwqa$
> ---
> drivers/usb/dwc3/core.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 7578c5133568..1550c39e792a 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1669,7 +1669,7 @@ static void dwc3_get_software_properties(struct dwc3 *dwc)
> }
> }
>
> -static void dwc3_get_properties(struct dwc3 *dwc)
> +static int dwc3_get_properties(struct dwc3 *dwc)
It doesn't make sense for dwc3_get_properties() to return -EPROBE_DEFER.
> {
> struct device *dev = dwc->dev;
> u8 lpm_nyet_threshold;
> @@ -1724,7 +1724,7 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> if (ret >= 0) {
> dwc->usb_psy = power_supply_get_by_name(usb_psy_name);
> if (!dwc->usb_psy)
> - dev_err(dev, "couldn't get usb power supply\n");
> + return dev_err_probe(dev, -EPROBE_DEFER, "couldn't get usb power supply\n");
> }
Move this logic (including power_supply_get_by_name()) outside of
dwc3_get_properties(). It doesn't belong here.
Thanks,
Thinh
>
> dwc->has_lpm_erratum = device_property_read_bool(dev,
> @@ -1847,6 +1847,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> dwc->imod_interval = 0;
>
> dwc->tx_fifo_resize_max_num = tx_fifo_resize_max_num;
> +
> + return 0;
> }
>
> /* check whether the core supports IMOD */
> @@ -2181,7 +2183,9 @@ static int dwc3_probe(struct platform_device *pdev)
> dwc->regs = regs;
> dwc->regs_size = resource_size(&dwc_res);
>
> - dwc3_get_properties(dwc);
> + ret = dwc3_get_properties(dwc);
> + if (ret)
> + return ret;
>
> dwc3_get_software_properties(dwc);
>
> --
> 2.47.1.688.g23fc6f90ad-goog
>
