It is possible that the usb power_supply is registered after the probe of dwc3. In this case, trying to get the usb power_supply during the probe will fail and there is no chance to try again. Also the usb power_supply might be unregistered at anytime so that the handle of it in dwc3 would become invalid. To fix this, get the handle right before calling to power_supply functions and put it afterward.

Fixes: 6f0764b5adea ("usb: dwc3: add a power supply for current control") Cc: stable@vger.kernel.org Signed-off-by: Kyle Tso kyletso@google.com --- drivers/usb/dwc3/core.c | 25 +++++-------------------- drivers/usb/dwc3/core.h | 4 ++-- drivers/usb/dwc3/gadget.c | 19 ++++++++++++++----- 3 files changed, 21 insertions(+), 27 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..ab563edd9b4c 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1631,8 +1631,6 @@ static void dwc3_get_properties(struct dwc3 *dwc) 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; @@ -1667,12 +1665,7 @@ static void dwc3_get_properties(struct dwc3 *dwc)

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"); - } + device_property_read_string(dev, "usb-psy-name", &dwc->usb_psy_name);

dwc->has_lpm_erratum = device_property_read_bool(dev, "snps,has-lpm-erratum"); @@ -2133,18 +2126,16 @@ static int dwc3_probe(struct platform_device *pdev) dwc3_get_software_properties(dwc);

dwc->reset = devm_reset_control_array_get_optional_shared(dev); - if (IS_ERR(dwc->reset)) { - ret = PTR_ERR(dwc->reset); - goto err_put_psy; - } + if (IS_ERR(dwc->reset)) + return PTR_ERR(dwc->reset);

ret = dwc3_get_clocks(dwc); if (ret) - goto err_put_psy; + return ret;

ret = reset_control_deassert(dwc->reset); if (ret) - goto err_put_psy; + return ret;

ret = dwc3_clk_enable(dwc); if (ret) @@ -2245,9 +2236,6 @@ static int dwc3_probe(struct platform_device *pdev) dwc3_clk_disable(dwc); err_assert_reset: reset_control_assert(dwc->reset); -err_put_psy: - if (dwc->usb_psy) - power_supply_put(dwc->usb_psy);

return ret; } @@ -2276,9 +2264,6 @@ static void dwc3_remove(struct platform_device *pdev) pm_runtime_set_suspended(&pdev->dev);

dwc3_free_event_buffers(dwc); - - if (dwc->usb_psy) - power_supply_put(dwc->usb_psy); }

#ifdef CONFIG_PM diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 1e561fd8b86e..ecfe2cc224f7 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1045,7 +1045,7 @@ struct dwc3_scratchpad_array { * @role_sw: usb_role_switch handle * @role_switch_default_mode: default operation mode of controller while * usb role is USB_ROLE_NONE. - * @usb_psy: pointer to power supply interface. + * @usb_psy_name: name of the usb power supply interface. * @usb2_phy: pointer to USB2 PHY * @usb3_phy: pointer to USB3 PHY * @usb2_generic_phy: pointer to array of USB2 PHYs @@ -1223,7 +1223,7 @@ struct dwc3 { struct usb_role_switch *role_sw; enum usb_dr_mode role_switch_default_mode;

- struct power_supply *usb_psy; + const char *usb_psy_name;

u32 fladj; u32 ref_clk_per; diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 89fc690fdf34..c89b5b5a64cf 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -3049,20 +3049,29 @@ static void dwc3_gadget_set_ssp_rate(struct usb_gadget *g,

static int dwc3_gadget_vbus_draw(struct usb_gadget *g, unsigned int mA) { - struct dwc3 *dwc = gadget_to_dwc(g); + struct dwc3 *dwc = gadget_to_dwc(g); + struct power_supply *usb_psy; union power_supply_propval val = {0}; int ret;

if (dwc->usb2_phy) return usb_phy_set_power(dwc->usb2_phy, mA);

- if (!dwc->usb_psy) + if (!dwc->usb_psy_name) return -EOPNOTSUPP;

- val.intval = 1000 * mA; - ret = power_supply_set_property(dwc->usb_psy, POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, &val); + usb_psy = power_supply_get_by_name(dwc->usb_psy_name); + if (usb_psy) { + val.intval = 1000 * mA; + ret = power_supply_set_property(usb_psy, POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, + &val); + power_supply_put(usb_psy); + return ret; + }

- return ret; + dev_err(dwc->dev, "couldn't get usb power supply\n"); + + return -EOPNOTSUPP; }

/**