| Message ID | 20201215202113.30394-2-digetx@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Support Runtime PM and host mode by Tegra ChipIdea USB driver | expand |
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
16.12.2020 11:51, Sergei Shtylyov пишет: > 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. Hi, I'll improve the comments in v2, thanks.
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 */ + usleep_range(2000, 2500); + return 0; }