usb: phy: tegra: Wait for VBUS wakeup status deassertion on suspend
Subsystems (2)
PATCH 1/2 usb: phy: tegra: Wait for VBUS wakeup status deassertion on suspend
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.
--- drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
drivers/usb/phy/phy-tegra-usb.c +10 -0
@@ -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 */
Signature · 1 line
2.30.2
PATCH 2/2 usb: phy: tegra: Correct definition of B_SESS_VLD_WAKEUP_EN bit
The B_SESS_VLD_WAKEUP_EN bit 6 was added by a mistake in a previous commit. This bit corresponds to B_SESS_END_WAKEUP_EN, which we don't use. The B_VBUS_VLD_WAKEUP_EN doesn't exist at all and B_SESS_VLD_WAKEUP_EN needs to be in place of it. We don't utilize B-sensors in the driver, so it never was a problem, nevertheless let's correct the definition of the bits.
--- drivers/usb/phy/phy-tegra-usb.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
drivers/usb/phy/phy-tegra-usb.c +2 -3
@@ -58,8 +58,7 @@#define USB_WAKEUP_DEBOUNCE_COUNT (x) (((x) & 0x7) << 16)#define USB_PHY_VBUS_SENSORS 0x404 -#define B_SESS_VLD_WAKEUP_EN BIT(6) -#define B_VBUS_VLD_WAKEUP_EN BIT(14) +#define B_SESS_VLD_WAKEUP_EN BIT(14)#define A_SESS_VLD_WAKEUP_EN BIT(22)#define A_VBUS_VLD_WAKEUP_EN BIT(30)
@@ -548,7 +547,7 @@ static int utmi_phy_power_on(struct tegra_usb_phy *phy) val =readl_relaxed (base +USB_PHY_VBUS_SENSORS ); val &= ~(A_VBUS_VLD_WAKEUP_EN |A_SESS_VLD_WAKEUP_EN ); - val &= ~(B_VBUS_VLD_WAKEUP_EN |B_SESS_VLD_WAKEUP_EN ); + val &= ~(B_SESS_VLD_WAKEUP_EN );writel_relaxed (val, base +USB_PHY_VBUS_SENSORS ); val =readl_relaxed (base +UTMIP_BAT_CHRG_CFG0 );
Signature · 1 line
2.30.2
Quoted 8 lines · Dmitry Osipenko
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.
Quoted 4 lines
Fixes 35192007d28d ("usb: phy: tegra: Support waking up from a low power mode")Reported-by Maxim Schwalm <[email protected]> # Asus TF700TSigned-off-by Dmitry Osipenko <[email protected]>
Quoted 35 lines
--- drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)drivers/usb/phy/phy-tegra-usb.c +10
-0@@ -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 */ Signature · 1 line
2.30.2
Signature · 2 lines
Thanks, Peter Chen
Quoted 31 lines · Dmitry Osipenko
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 <[email protected]> # Asus TF700TSigned-off-by Dmitry Osipenko <[email protected]>--- drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)drivers/usb/phy/phy-tegra-usb.c +1
-0@@ -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;
drivers/usb/phy/phy-tegra-usb.c static int utmi_phy_power_off(struct tegra_usb_phy *phy) · line 657
Quoted 10 lines
drivers/usb/phy/phy-tegra-usb.c +9
-0+/* +* 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?
Signature · 2 lines
Thanks, Peter Chen
15.06.2021 04:05, Peter Chen пишет:
Quoted 33 lines · Dmitry Osipenko
Quoted 32 lines
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 <[email protected]> # Asus TF700TSigned-off-by Dmitry Osipenko <[email protected]>--- drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)drivers/usb/phy/phy-tegra-usb.c +1
-0@@ -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;
Quoted 12 lines
drivers/usb/phy/phy-tegra-usb.c static int utmi_phy_power_off(struct tegra_usb_phy *phy) · line 657
Quoted 9 lines
drivers/usb/phy/phy-tegra-usb.c +9
-0+/* +* 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.
Quoted 31 lines · Dmitry Osipenko
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 <[email protected]> # Asus TF700TSigned-off-by Dmitry Osipenko <[email protected]>--- drivers/usb/phy/phy-tegra-usb.c | 10 ++++++++++ 1 file changed, 10 insertions(+)drivers/usb/phy/phy-tegra-usb.c +1
-0@@ -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;
drivers/usb/phy/phy-tegra-usb.c static int utmi_phy_power_off(struct tegra_usb_phy *phy) · line 657
Quoted 10 lines
drivers/usb/phy/phy-tegra-usb.c +9
-0+/* +* 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 ); +
Quoted 6 lines
drivers/usb/phy/phy-tegra-usb.c +0
-0utmi_phy_clk_disable (phy);/* PHY won't resume if reset is asserted */ Signature · 1 line
2.30.2
Signature · 2 lines
Thanks, Peter Chen