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* [PATCH] usb: dwc3: Update soft-reset wait polling rate
@ 2019-08-08 23:39 Thinh Nguyen
  0 siblings, 0 replies; only message in thread
From: Thinh Nguyen @ 2019-08-08 23:39 UTC (permalink / raw)
  To: Felipe Balbi, linux-usb; +Cc: John Youn, Thinh Nguyen

Starting from DWC_usb31 version 1.90a and later, the DCTL.CSFRST bit
will not be cleared until after all the internal clocks are synchronized
during soft-reset. This may take a little more than 50ms. Set the
polling rate at 20ms instead.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
---
 drivers/usb/dwc3/core.c | 23 ++++++++++++++++++-----
 drivers/usb/dwc3/core.h |  2 ++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 98bce85c29d0..252c397860ef 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -252,12 +252,25 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
 	reg |= DWC3_DCTL_CSFTRST;
 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
 
+	/*
+	 * For DWC_usb31 controller 1.90a and later, the DCTL.CSFRST bit
+	 * is cleared only after all the clocks are synchronized. This can
+	 * take a little more than 50ms. Set the polling rate at 20ms
+	 * for 10 times instead.
+	 */
+	if (dwc3_is_usb31(dwc) && dwc->revision >= DWC3_USB31_REVISION_190A)
+		retries = 10;
+
 	do {
 		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 		if (!(reg & DWC3_DCTL_CSFTRST))
 			goto done;
 
-		udelay(1);
+		if (dwc3_is_usb31(dwc) &&
+		    dwc->revision >= DWC3_USB31_REVISION_190A)
+			msleep(20);
+		else
+			udelay(1);
 	} while (--retries);
 
 	phy_exit(dwc->usb3_generic_phy);
@@ -267,11 +280,11 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
 
 done:
 	/*
-	 * For DWC_usb31 controller, once DWC3_DCTL_CSFTRST bit is cleared,
-	 * we must wait at least 50ms before accessing the PHY domain
-	 * (synchronization delay). DWC_usb31 programming guide section 1.3.2.
+	 * For DWC_usb31 controller 1.80a and prior, once DCTL.CSFRST bit
+	 * is cleared, we must wait at least 50ms before accessing the PHY
+	 * domain (synchronization delay).
 	 */
-	if (dwc3_is_usb31(dwc))
+	if (dwc3_is_usb31(dwc) && dwc->revision <= DWC3_USB31_REVISION_180A)
 		msleep(50);
 
 	return 0;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 3dd783b889cb..1c8b349379af 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1137,6 +1137,8 @@ struct dwc3 {
 #define DWC3_USB31_REVISION_120A	(0x3132302a | DWC3_REVISION_IS_DWC31)
 #define DWC3_USB31_REVISION_160A	(0x3136302a | DWC3_REVISION_IS_DWC31)
 #define DWC3_USB31_REVISION_170A	(0x3137302a | DWC3_REVISION_IS_DWC31)
+#define DWC3_USB31_REVISION_180A	(0x3138302a | DWC3_REVISION_IS_DWC31)
+#define DWC3_USB31_REVISION_190A	(0x3139302a | DWC3_REVISION_IS_DWC31)
 
 	u32			version_type;
 
-- 
2.11.0


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2019-08-08 23:39 [PATCH] usb: dwc3: Update soft-reset wait polling rate Thinh Nguyen

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