| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 36/96] usb: dwc3: Add SoftReset PHY synchonization delay | Date | Thu, 24 May 2018 11:38:19 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
[ Upstream commit fab3833338779e1e668bd58d1f76d601657304b8 ]
>From DWC_usb31 programming guide section 1.3.2, once DWC3_DCTL_CSFTRST bit is cleared, we must wait at least 50ms before accessing the PHY domain (synchronization delay).
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/usb/dwc3/core.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -161,7 +161,7 @@ static int dwc3_core_soft_reset(struct d do { reg = dwc3_readl(dwc->regs, DWC3_DCTL); if (!(reg & DWC3_DCTL_CSFTRST)) - return 0; + goto done; udelay(1); } while (--retries); @@ -170,6 +170,17 @@ static int dwc3_core_soft_reset(struct d phy_exit(dwc->usb2_generic_phy); return -ETIMEDOUT; + +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. + */ + if (dwc3_is_usb31(dwc)) + msleep(50); + + return 0; } /**
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