Hi Roger, On 05/05/23 6:02 pm, Roger Quadros wrote: > Hi Ravi, > > On 05/05/2023 15:13, Ravi Gunasekaran wrote: >> From: Aswath Govindraju <a-govindr...@ti.com> >> >> When the device port is in a low power state [U3/L2/Not Connected], >> accesses to usb device registers may take a long time. This could lead to >> potential core hang when the controller registers are accessed after the >> port is disabled by setting DEVDS field. Setting the fast register access >> bit ensures that the PHY clock is keeping up in active state. >> >> Therefore, set fast access bit to ensure the accesses to device registers >> are quick even in low power states. >> >> Signed-off-by: Aswath Govindraju <a-govindr...@ti.com> >> --- >> drivers/usb/cdns3/gadget.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c >> index fcaeab9cc1..fddc8c931a 100644 >> --- a/drivers/usb/cdns3/gadget.c >> +++ b/drivers/usb/cdns3/gadget.c >> @@ -2321,6 +2321,9 @@ static void cdns3_gadget_config(struct cdns3_device >> *priv_dev) >> writel(USB_IEN_INIT, ®s->usb_ien); >> writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, ®s->usb_conf); >> >> + /* Set the Fast access bit */ >> + writel(PUSB_PWR_FST_REG_ACCESS, &priv_dev->regs->usb_pwr); >> + > > Should this be done in cdns3_gadget_udc_start() so it is symmetric? >
cdns3_gadget_config() is called in cdns3_gadget_udc_start() and cdns3_gadget_resume(). These settings seems to be needed during resume as well. >> cdns3_configure_dmult(priv_dev, NULL); >> >> cdns3_gadget_pullup(&priv_dev->gadget, 1); >> @@ -2378,6 +2381,7 @@ static int cdns3_gadget_udc_stop(struct usb_gadget >> *gadget) >> >> /* disable interrupt for device */ >> writel(0, &priv_dev->regs->usb_ien); >> + writel(0, &priv_dev->regs->usb_pwr); >> writel(USB_CONF_DEVDS, &priv_dev->regs->usb_conf); >> >> return ret; >> >> base-commit: a25dcda452bf6a6de72764a8d990d72e5def643d > > cheers, > -roger -- Regards, Ravi
