From bc27117c7cdd4b57d0f079620b483f3b229074bd Mon Sep 17 00:00:00 2001
From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Date: Mon, 29 Nov 2021 18:53:09 -0800
Subject: [PATCH] usb: dwc3: gadget: Skip checking Update Transfer status
Git-commit: bc27117c7cdd4b57d0f079620b483f3b229074bd
References: git-fixes
Patch-mainline: v5.17-rc1

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>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/dwc3/gadget.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7e3db00e9759..00b3f19c4d3e 100644
--- 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) {
-- 
2.35.3