usb: dwc3: gadget: Skip checking Update Transfer status

If we're not setting CMDACT (from "No Response" Update Transfer
command), then there's no point in checking for the command status. So
skip it. This can reduce a register read delay and improve performance.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/3dc31cf11581ae3ee82d9202dda3fc17d897d786.1638240306.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7e3db00e9759529579af1c11dd12c9f4ab821937..00b3f19c4d3efab260d6d6d178058219bbce533b 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -357,6 +357,12 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd,
                cmd |= DWC3_DEPCMD_CMDACT;
 
        dwc3_writel(dep->regs, DWC3_DEPCMD, cmd);
+
+       if (!(cmd & DWC3_DEPCMD_CMDACT)) {
+               ret = 0;
+               goto skip_status;
+       }
+
        do {
                reg = dwc3_readl(dep->regs, DWC3_DEPCMD);
                if (!(reg & DWC3_DEPCMD_CMDACT)) {
@@ -398,6 +404,7 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd,
                cmd_status = -ETIMEDOUT;
        }
 
+skip_status:
        trace_dwc3_gadget_ep_cmd(dep, cmd, params, cmd_status);
 
        if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {