6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kyle Tso kyletso@google.com
commit 66e0ea341a2a78d14336117f19763bd9be26d45d upstream.
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 stable@kernel.org Signed-off-by: Kyle Tso kyletso@google.com Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/20250115044548.2701138-1-kyletso@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/core.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-)
--- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1505,8 +1505,6 @@ static void dwc3_get_properties(struct d u8 tx_thr_num_pkt_prd = 0; u8 tx_max_burst_prd = 0; u8 tx_fifo_resize_max_num; - const char *usb_psy_name; - int ret;
/* default to highest possible threshold */ lpm_nyet_threshold = 0xf; @@ -1541,13 +1539,6 @@ static void dwc3_get_properties(struct d
dwc->sys_wakeup = device_may_wakeup(dwc->sysdev);
- ret = device_property_read_string(dev, "usb-psy-name", &usb_psy_name); - 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"); - } - dwc->has_lpm_erratum = device_property_read_bool(dev, "snps,has-lpm-erratum"); device_property_read_u8(dev, "snps,lpm-nyet-threshold", @@ -1887,6 +1878,23 @@ static int dwc3_get_clocks(struct dwc3 * return 0; }
+static struct power_supply *dwc3_get_usb_power_supply(struct dwc3 *dwc) +{ + struct power_supply *usb_psy; + const char *usb_psy_name; + int ret; + + ret = device_property_read_string(dwc->dev, "usb-psy-name", &usb_psy_name); + if (ret < 0) + return NULL; + + usb_psy = power_supply_get_by_name(usb_psy_name); + if (!usb_psy) + return ERR_PTR(-EPROBE_DEFER); + + return usb_psy; +} + static int dwc3_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -1940,6 +1948,10 @@ static int dwc3_probe(struct platform_de
dwc3_get_properties(dwc);
+ dwc->usb_psy = dwc3_get_usb_power_supply(dwc); + if (IS_ERR(dwc->usb_psy)) + return dev_err_probe(dev, PTR_ERR(dwc->usb_psy), "couldn't get usb power supply\n"); + dwc->reset = devm_reset_control_array_get_optional_shared(dev); if (IS_ERR(dwc->reset)) { ret = PTR_ERR(dwc->reset);