Messages in this thread | | | Subject | Re: [PATCH v1 1/8] usb: phy: tegra: Add delay after power up | From | Sergei Shtylyov <> | Date | Wed, 16 Dec 2020 11:51:14 +0300 |
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Hello!
On 15.12.2020 23:21, Dmitry Osipenko wrote:
> The PHY hardware needs the delay of 2ms after power up, otherwise initial > interrupt may be lost if USB controller is accessed before PHY is settled > down. Previously this issue was masked by implicit delays, but now it pops > up after squashing the older ehci-tegra driver into the ChipIdea driver. > > Tested-by: Matt Merhar <mattmerhar@protonmail.com> > Tested-by: Nicolas Chauvet <kwizart@gmail.com> > Tested-by: Peter Geis <pgwipeout@gmail.com> > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/usb/phy/phy-tegra-usb.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c > index 03a333797382..cee9c9dbb775 100644 > --- a/drivers/usb/phy/phy-tegra-usb.c > +++ b/drivers/usb/phy/phy-tegra-usb.c > @@ -784,6 +784,9 @@ static int tegra_usb_phy_power_on(struct tegra_usb_phy *phy) > > phy->powered_on = true; > > + /* let PHY to settle down */
Let the PHY settle down.
> + usleep_range(2000, 2500); > + > return 0; > } >
MBR, Sergei
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