diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 4ed8b34540f2..45782d7ec67b 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -233,6 +233,7 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc); int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd, struct dwc3_gadget_ep_cmd_params *params) { + const struct usb_endpoint_descriptor *desc = dep->endpoint.desc; struct dwc3 *dwc = dep->dwc; u32 timeout = 500; u32 reg; @@ -276,7 +277,28 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd, dwc3_writel(dep->regs, DWC3_DEPCMDPAR1, params->param1); dwc3_writel(dep->regs, DWC3_DEPCMDPAR2, params->param2); - dwc3_writel(dep->regs, DWC3_DEPCMD, cmd | DWC3_DEPCMD_CMDACT); + /* + * Synopsys Databook 2.60a states in section 6.3.2.5.6 of that if we're + * not relying on XferNotReady, we can make use of a special "No + * Response Update Transfer" command where we should clear both CmdAct + * and CmdIOC bits. + * + * With this, we don't need to wait for command completion and can + * straight away issue further commands to the endpoint. + * + * NOTICE: We're making an assumption that control endpoints will never + * make use of Update Transfer command. This is a safe assumption + * because we can never have more than one request at a time with + * Control Endpoints. If anybody changes that assumption, this chunk + * needs to be updated accordingly. + */ + if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_UPDATETRANSFER && + !usb_endpoint_xfer_isoc(desc)) + cmd &= ~(DWC3_DEPCMD_CMDIOC | DWC3_DEPCMD_CMDACT); + else + cmd |= DWC3_DEPCMD_CMDACT; + + dwc3_writel(dep->regs, DWC3_DEPCMD, cmd); do { reg = dwc3_readl(dep->regs, DWC3_DEPCMD); if (!(reg & DWC3_DEPCMD_CMDACT)) { |