| Message ID | 20210613145936.9902-1-digetx@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/2] usb: phy: tegra: Wait for VBUS wakeup status deassertion on suspend | expand |
On 21-06-13 17:59:35, Dmitry Osipenko wrote: > Some devices need an extra delay after losing VBUS, otherwise VBUS may > be detected as active at suspend time, preventing the PHY's suspension > by the VBUS detection sensor. This problem was found on Asus Transformer > TF700T (Tegra30) tablet device, where the USB PHY wakes up immediately > from suspend because VBUS sensor continues to detect VBUS as active after > disconnection. We need to poll the PHY's VBUS wakeup status until it's > deasserted before suspending PHY in order to fix this minor trouble. > > Fixes: 35192007d28d ("usb: phy: tegra: Support waking up from a low power mode") > Reported-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T > Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c > index fc5c6cab58ba..ff482c694200 100644 > --- a/drivers/usb/phy/phy-tegra-usb.c > +++ b/drivers/usb/phy/phy-tegra-usb.c > @@ -64,6 +64,7 @@ > #define A_VBUS_VLD_WAKEUP_EN BIT(30) > > #define USB_PHY_VBUS_WAKEUP_ID 0x408 > +#define VBUS_WAKEUP_STS BIT(10) > #define VBUS_WAKEUP_WAKEUP_EN BIT(30) > > #define USB1_LEGACY_CTRL 0x410 > @@ -645,6 +646,15 @@ static int utmi_phy_power_off(struct tegra_usb_phy *phy) > void __iomem *base = phy->regs; > u32 val; > > + /* > + * Give hardware time to settle down after VBUS disconnection, > + * otherwise PHY will immediately wake up from suspend. > + */ > + if (phy->wakeup_enabled && phy->mode != USB_DR_MODE_HOST) > + readl_relaxed_poll_timeout(base + USB_PHY_VBUS_WAKEUP_ID, > + val, !(val & VBUS_WAKEUP_STS), > + 5000, 100000); > + Where will clear VBUS_WAKEUP_STS? Or it will be cleared by HW after VBUS lower than B Session Valid? -- Thanks, Peter Chen
On 21-06-13 17:59:35, Dmitry Osipenko wrote: > Some devices need an extra delay after losing VBUS, otherwise VBUS may > be detected as active at suspend time, preventing the PHY's suspension > by the VBUS detection sensor. This problem was found on Asus Transformer > TF700T (Tegra30) tablet device, where the USB PHY wakes up immediately > from suspend because VBUS sensor continues to detect VBUS as active after > disconnection. We need to poll the PHY's VBUS wakeup status until it's > deasserted before suspending PHY in order to fix this minor trouble. > > Fixes: 35192007d28d ("usb: phy: tegra: Support waking up from a low power mode") > Reported-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T > Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Peter Chen <peter.chen@kernel.org> > --- > drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c > index fc5c6cab58ba..ff482c694200 100644 > --- a/drivers/usb/phy/phy-tegra-usb.c > +++ b/drivers/usb/phy/phy-tegra-usb.c > @@ -64,6 +64,7 @@ > #define A_VBUS_VLD_WAKEUP_EN BIT(30) > > #define USB_PHY_VBUS_WAKEUP_ID 0x408 > +#define VBUS_WAKEUP_STS BIT(10) > #define VBUS_WAKEUP_WAKEUP_EN BIT(30) > > #define USB1_LEGACY_CTRL 0x410 > @@ -645,6 +646,15 @@ static int utmi_phy_power_off(struct tegra_usb_phy *phy) > void __iomem *base = phy->regs; > u32 val; > > + /* > + * Give hardware time to settle down after VBUS disconnection, > + * otherwise PHY will immediately wake up from suspend. > + */ > + if (phy->wakeup_enabled && phy->mode != USB_DR_MODE_HOST) > + readl_relaxed_poll_timeout(base + USB_PHY_VBUS_WAKEUP_ID, > + val, !(val & VBUS_WAKEUP_STS), > + 5000, 100000); > + > utmi_phy_clk_disable(phy); > > /* PHY won't resume if reset is asserted */ > -- > 2.30.2 > -- Thanks, Peter Chen
15.06.2021 04:05, Peter Chen пишет: > On 21-06-13 17:59:35, Dmitry Osipenko wrote: >> Some devices need an extra delay after losing VBUS, otherwise VBUS may >> be detected as active at suspend time, preventing the PHY's suspension >> by the VBUS detection sensor. This problem was found on Asus Transformer >> TF700T (Tegra30) tablet device, where the USB PHY wakes up immediately >> from suspend because VBUS sensor continues to detect VBUS as active after >> disconnection. We need to poll the PHY's VBUS wakeup status until it's >> deasserted before suspending PHY in order to fix this minor trouble. >> >> Fixes: 35192007d28d ("usb: phy: tegra: Support waking up from a low power mode") >> Reported-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T >> Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >> --- >> drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c >> index fc5c6cab58ba..ff482c694200 100644 >> --- a/drivers/usb/phy/phy-tegra-usb.c >> +++ b/drivers/usb/phy/phy-tegra-usb.c >> @@ -64,6 +64,7 @@ >> #define A_VBUS_VLD_WAKEUP_EN BIT(30) >> >> #define USB_PHY_VBUS_WAKEUP_ID 0x408 >> +#define VBUS_WAKEUP_STS BIT(10) >> #define VBUS_WAKEUP_WAKEUP_EN BIT(30) >> >> #define USB1_LEGACY_CTRL 0x410 >> @@ -645,6 +646,15 @@ static int utmi_phy_power_off(struct tegra_usb_phy *phy) >> void __iomem *base = phy->regs; >> u32 val; >> >> + /* >> + * Give hardware time to settle down after VBUS disconnection, >> + * otherwise PHY will immediately wake up from suspend. >> + */ >> + if (phy->wakeup_enabled && phy->mode != USB_DR_MODE_HOST) >> + readl_relaxed_poll_timeout(base + USB_PHY_VBUS_WAKEUP_ID, >> + val, !(val & VBUS_WAKEUP_STS), >> + 5000, 100000); >> + > > Where will clear VBUS_WAKEUP_STS? Or it will be cleared by HW after VBUS lower than > B Session Valid? It's cleared by hardware. Tegra documentation doesn't explicitly saying what voltage level is used by the VBUS_WAKEUP sensor, but it implies the session-valid level. There are two sensors that could be used for detection of cable-insertion into B-device USB port of Tegra: VBUS_WAKEUP and A_SESS_VLD (from perspective of Tegra as a B-device). The VBUS_WAKEUP sensor may not work in some hardware configurations, always outputting 0. Seems it depends on whether port is OTG-capable (VBUS_WAKEUP works) or fixed to a device mode. IIUC, only VBUS_WAKEUP sensor can generate wake event that can resume system for a deepest suspend state.
On 21-06-13 17:59:35, Dmitry Osipenko wrote: > Some devices need an extra delay after losing VBUS, otherwise VBUS may > be detected as active at suspend time, preventing the PHY's suspension > by the VBUS detection sensor. This problem was found on Asus Transformer > TF700T (Tegra30) tablet device, where the USB PHY wakes up immediately > from suspend because VBUS sensor continues to detect VBUS as active after > disconnection. We need to poll the PHY's VBUS wakeup status until it's > deasserted before suspending PHY in order to fix this minor trouble. > > Fixes: 35192007d28d ("usb: phy: tegra: Support waking up from a low power mode") > Reported-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T > Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c > index fc5c6cab58ba..ff482c694200 100644 > --- a/drivers/usb/phy/phy-tegra-usb.c > +++ b/drivers/usb/phy/phy-tegra-usb.c > @@ -64,6 +64,7 @@ > #define A_VBUS_VLD_WAKEUP_EN BIT(30) > > #define USB_PHY_VBUS_WAKEUP_ID 0x408 > +#define VBUS_WAKEUP_STS BIT(10) > #define VBUS_WAKEUP_WAKEUP_EN BIT(30) > > #define USB1_LEGACY_CTRL 0x410 > @@ -645,6 +646,15 @@ static int utmi_phy_power_off(struct tegra_usb_phy *phy) > void __iomem *base = phy->regs; > u32 val; > > + /* > + * Give hardware time to settle down after VBUS disconnection, > + * otherwise PHY will immediately wake up from suspend. > + */ > + if (phy->wakeup_enabled && phy->mode != USB_DR_MODE_HOST) > + readl_relaxed_poll_timeout(base + USB_PHY_VBUS_WAKEUP_ID, > + val, !(val & VBUS_WAKEUP_STS), > + 5000, 100000); > + Reviewed-by: Peter Chen <peter.chen@kernel.org> > utmi_phy_clk_disable(phy); > > /* PHY won't resume if reset is asserted */ > -- > 2.30.2 > -- Thanks, Peter Chen
diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c index fc5c6cab58ba..ff482c694200 100644 --- a/drivers/usb/phy/phy-tegra-usb.c +++ b/drivers/usb/phy/phy-tegra-usb.c @@ -64,6 +64,7 @@ #define A_VBUS_VLD_WAKEUP_EN BIT(30) #define USB_PHY_VBUS_WAKEUP_ID 0x408 +#define VBUS_WAKEUP_STS BIT(10) #define VBUS_WAKEUP_WAKEUP_EN BIT(30) #define USB1_LEGACY_CTRL 0x410 @@ -645,6 +646,15 @@ static int utmi_phy_power_off(struct tegra_usb_phy *phy) void __iomem *base = phy->regs; u32 val; + /* + * Give hardware time to settle down after VBUS disconnection, + * otherwise PHY will immediately wake up from suspend. + */ + if (phy->wakeup_enabled && phy->mode != USB_DR_MODE_HOST) + readl_relaxed_poll_timeout(base + USB_PHY_VBUS_WAKEUP_ID, + val, !(val & VBUS_WAKEUP_STS), + 5000, 100000); + utmi_phy_clk_disable(phy); /* PHY won't resume if reset is asserted */
Some devices need an extra delay after losing VBUS, otherwise VBUS may be detected as active at suspend time, preventing the PHY's suspension by the VBUS detection sensor. This problem was found on Asus Transformer TF700T (Tegra30) tablet device, where the USB PHY wakes up immediately from suspend because VBUS sensor continues to detect VBUS as active after disconnection. We need to poll the PHY's VBUS wakeup status until it's deasserted before suspending PHY in order to fix this minor trouble. Fixes: 35192007d28d ("usb: phy: tegra: Support waking up from a low power mode") Reported-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)