From: Serge Semin Date: Thu, 10 Dec 2020 08:50:06 +0000 (+0300) Subject: usb: dwc3: ulpi: Use VStsDone to detect PHY regs access completion X-Git-Tag: v4.14.215~28 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8a950124e7936ffa990ac39c6bbf7d42ad8cb373;p=users%2Fdwmw2%2Flinux.git usb: dwc3: ulpi: Use VStsDone to detect PHY regs access completion commit ce722da66d3e9384aa2de9d33d584ee154e5e157 upstream. In accordance with [1] the DWC_usb3 core sets the GUSB2PHYACCn.VStsDone bit when the PHY vendor control access is done and clears it when the application initiates a new transaction. The doc doesn't say anything about the GUSB2PHYACCn.VStsBsy flag serving for the same purpose. Moreover we've discovered that the VStsBsy flag can be cleared before the VStsDone bit. So using the former as a signal of the PHY control registers completion might be dangerous. Let's have the VStsDone flag utilized instead then. [1] Synopsys DesignWare Cores SuperSpeed USB 3.0 xHCI Host Controller Databook, 2.70a, December 2013, p.388 Fixes: 88bc9d194ff6 ("usb: dwc3: add ULPI interface support") Acked-by: Heikki Krogerus Signed-off-by: Serge Semin Link: https://lore.kernel.org/r/20201210085008.13264-2-Sergey.Semin@baikalelectronics.ru Cc: stable Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 8747f9f02229e..8c59a8aeb9409 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -227,6 +227,7 @@ /* Global USB2 PHY Vendor Control Register */ #define DWC3_GUSB2PHYACC_NEWREGREQ BIT(25) +#define DWC3_GUSB2PHYACC_DONE BIT(24) #define DWC3_GUSB2PHYACC_BUSY BIT(23) #define DWC3_GUSB2PHYACC_WRITE BIT(22) #define DWC3_GUSB2PHYACC_ADDR(n) (n << 16) diff --git a/drivers/usb/dwc3/ulpi.c b/drivers/usb/dwc3/ulpi.c index e87ce8e9edee9..d3b68e97096e7 100644 --- a/drivers/usb/dwc3/ulpi.c +++ b/drivers/usb/dwc3/ulpi.c @@ -27,7 +27,7 @@ static int dwc3_ulpi_busyloop(struct dwc3 *dwc) while (count--) { reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0)); - if (!(reg & DWC3_GUSB2PHYACC_BUSY)) + if (reg & DWC3_GUSB2PHYACC_DONE) return 0; cpu_relax(); }