usb: dwc3: gadget: put link to U0 before Start Transfer (c36d8e94) · Commits · 戴 / test

Synopsys Databook says we should move link to U0 before issuing a Start Transfer command. We could require the gadget driver to call usb_gadget_wakeup() however I feel that changing all gadget drivers to keep track of Link State and conditionally call usb_gadget_wakeup() would be far too much work. For now we will handle this at the UDC level, but at some point composite.c should be one handling this. Signed-off-by:

Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -221,6 +221,8 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
		} while (1);
		}

		static int __dwc3_gadget_wakeup(struct dwc3 *dwc);

		int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
		unsigned cmd, struct dwc3_gadget_ep_cmd_params *params)
		{
		@@ -248,6 +250,20 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
		}

		if (cmd == DWC3_DEPCMD_STARTTRANSFER) {
		int needs_wakeup;

		needs_wakeup = (dwc->link_state == DWC3_LINK_STATE_U1 \|\|
		dwc->link_state == DWC3_LINK_STATE_U2 \|\|
		dwc->link_state == DWC3_LINK_STATE_U3);

		if (unlikely(needs_wakeup)) {
		ret = __dwc3_gadget_wakeup(dwc);
		dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
		ret);
		}
		}

		dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
		dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
		dwc3_writel(dwc->regs, DWC3_DEPCMDPAR2(ep), params->param2);

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