Hi, Serge Semin <sergey.se...@baikalelectronics.ru> writes:
> 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
>
> Signed-off-by: Serge Semin <sergey.se...@baikalelectronics.ru>
> ---
> drivers/usb/dwc3/core.h | 1 +
> drivers/usb/dwc3/ulpi.c | 2 +-
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 2f04b3e42bf1..8d5e5bba1bc2 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -284,6 +284,7 @@
>
> /* 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 e6e6176386a4..20f5d9aba317 100644
> --- a/drivers/usb/dwc3/ulpi.c
> +++ b/drivers/usb/dwc3/ulpi.c
> @@ -24,7 +24,7 @@ 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)
are you sure this works in all supported versions of the core?
John, could you confirm this for us?
thanks
--
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