drivers: usb: dwc3: A question...

From: Gustavo A. R. Silva
Date: Thu Feb 09 2017 - 04:35:39 EST


Hello everybody,

I ran into the following piece of code at drivers/usb/dwc3/dwc3-omap.c:218 (linux-next)

218static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
219 enum omap_dwc3_vbus_id_status status)
220{
221 int ret;
222 u32 val;
223
224 switch (status) {
225 case OMAP_DWC3_ID_GROUND:
226 if (omap->vbus_reg) {
227 ret = regulator_enable(omap->vbus_reg);
228 if (ret) {
229 dev_err(omap->dev, "regulator enable failed\n");
230 return;
231 }
232 }
233
234 val = dwc3_omap_read_utmi_ctrl(omap);
235 val &= ~USBOTGSS_UTMI_OTG_CTRL_IDDIG;
236 dwc3_omap_write_utmi_ctrl(omap, val);
237 break;
238
239 case OMAP_DWC3_VBUS_VALID:
240 val = dwc3_omap_read_utmi_ctrl(omap);
241 val &= ~USBOTGSS_UTMI_OTG_CTRL_SESSEND;
242 val |= USBOTGSS_UTMI_OTG_CTRL_VBUSVALID
243 | USBOTGSS_UTMI_OTG_CTRL_SESSVALID;
244 dwc3_omap_write_utmi_ctrl(omap, val);
245 break;
246
247 case OMAP_DWC3_ID_FLOAT:
248 if (omap->vbus_reg)
249 regulator_disable(omap->vbus_reg);
250 val = dwc3_omap_read_utmi_ctrl(omap);
251 val |= USBOTGSS_UTMI_OTG_CTRL_IDDIG;
252 dwc3_omap_write_utmi_ctrl(omap, val);
253
254 case OMAP_DWC3_VBUS_OFF:
255 val = dwc3_omap_read_utmi_ctrl(omap);
256 val &= ~(USBOTGSS_UTMI_OTG_CTRL_SESSVALID
257 | USBOTGSS_UTMI_OTG_CTRL_VBUSVALID);
258 val |= USBOTGSS_UTMI_OTG_CTRL_SESSEND;
259 dwc3_omap_write_utmi_ctrl(omap, val);
260 break;
261
262 default:
263 dev_WARN(omap->dev, "invalid state\n");
264 }
265}

The thing is that the case for OMAP_DWC3_ID_FLOAT is not terminated by a break statement, and it falls through to the next case OMAP_DWC3_VBUS_OFF.

My question here is if for any reason this code is intentional?

In case it is not, I will write a patch to fix this, but first it would be great to hear any comment about it.

Thank you
--
Gustavo A. R. Silva