From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
To: Felipe Balbi <balbi@kernel.org>, <linux-usb@vger.kernel.org>
Cc: John Youn <John.Youn@synopsys.com>,
Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Subject: [PATCH] usb: dwc3: Update soft-reset wait polling rate
Date: Thu, 8 Aug 2019 16:39:42 -0700 [thread overview]
Message-ID: <ac09fd05a411b585a73dde6b6745c79ec9123743.1565307304.git.thinhn@synopsys.com> (raw)
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
reply other threads:[~2019-08-08 23:39 UTC|newest]
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