From b01b03f3ad82b4293f6ca4da9b2692b6a377c609 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 28 Apr 2008 11:06:11 -0400 Subject: [PATCH] USB: add new routine for checking port-resume type This patch (as1070) creates a new subroutine to check whether a device can be resumed. This code is needed even when CONFIG_USB_SUSPEND isn't set, because devices do suspend themselves when the root hub (and hence the entire bus) is suspended, and power sessions can get lost during a system sleep even without individual port suspends. The patch also fixes a loose end in USB-Persist reset-resume handling. When a low- or full-speed device is attached to an EHCI's companion controller, the port handoff during resume will cause the companion port's connect-status-change feature to be set. If that flag isn't cleared, the port-reset code will think it indicates that the device has been unplugged and the reset-resume will fail. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 89 ++++++++++++++++++++++++++++++------------ 1 file changed, 63 insertions(+), 26 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 2a5c2833de38..d14da2123eb5 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1821,6 +1821,45 @@ static int hub_port_reset(struct usb_hub *hub, int port1, #ifdef CONFIG_PM +#define MASK_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \ + USB_PORT_STAT_SUSPEND) +#define WANT_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION) + +/* Determine whether the device on a port is ready for a normal resume, + * is ready for a reset-resume, or should be disconnected. + */ +static int check_port_resume_type(struct usb_device *udev, + struct usb_hub *hub, int port1, + int status, unsigned portchange, unsigned portstatus) +{ + /* Is the device still present? */ + if (status || (portstatus & MASK_BITS) != WANT_BITS) { + if (status >= 0) + status = -ENODEV; + } + + /* Can't do a normal resume if the port isn't enabled */ + else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) + status = -ENODEV; + + if (status) { + dev_dbg(hub->intfdev, + "port %d status %04x.%04x after resume, %d\n", + port1, portchange, portstatus, status); + } else if (udev->reset_resume) { + + /* Late port handoff can set status-change bits */ + if (portchange & USB_PORT_STAT_C_CONNECTION) + clear_port_feature(hub->hdev, port1, + USB_PORT_FEAT_C_CONNECTION); + if (portchange & USB_PORT_STAT_C_ENABLE) + clear_port_feature(hub->hdev, port1, + USB_PORT_FEAT_C_ENABLE); + } + + return status; +} + #ifdef CONFIG_USB_SUSPEND /* @@ -2025,7 +2064,6 @@ int usb_port_resume(struct usb_device *udev) int port1 = udev->portnum; int status; u16 portchange, portstatus; - unsigned mask_flags, want_flags; /* Skip the initial Clear-Suspend step for a remote wakeup */ status = hub_port_status(hub, port1, &portstatus, &portchange); @@ -2054,35 +2092,23 @@ int usb_port_resume(struct usb_device *udev) */ status = hub_port_status(hub, port1, &portstatus, &portchange); - SuspendCleared: - if (udev->reset_resume) - want_flags = USB_PORT_STAT_POWER - | USB_PORT_STAT_CONNECTION; - else - want_flags = USB_PORT_STAT_POWER - | USB_PORT_STAT_CONNECTION - | USB_PORT_STAT_ENABLE; - mask_flags = want_flags | USB_PORT_STAT_SUSPEND; + /* TRSMRCY = 10 msec */ + msleep(10); + } - if (status < 0 || (portstatus & mask_flags) != want_flags) { - dev_dbg(hub->intfdev, - "port %d status %04x.%04x after resume, %d\n", - port1, portchange, portstatus, status); - if (status >= 0) - status = -ENODEV; - } else { - if (portchange & USB_PORT_STAT_C_SUSPEND) - clear_port_feature(hub->hdev, port1, - USB_PORT_FEAT_C_SUSPEND); - /* TRSMRCY = 10 msec */ - msleep(10); - } + SuspendCleared: + if (status == 0) { + if (portchange & USB_PORT_STAT_C_SUSPEND) + clear_port_feature(hub->hdev, port1, + USB_PORT_FEAT_C_SUSPEND); } clear_bit(port1, hub->busy_bits); if (!hub->hdev->parent && !hub->busy_bits[0]) usb_enable_root_hub_irq(hub->hdev->bus); + status = check_port_resume_type(udev, + hub, port1, status, portchange, portstatus); if (status == 0) status = finish_port_resume(udev); if (status < 0) { @@ -2115,12 +2141,23 @@ int usb_port_suspend(struct usb_device *udev) return 0; } +/* However we may need to do a reset-resume */ + int usb_port_resume(struct usb_device *udev) { - int status = 0; + struct usb_hub *hub = hdev_to_hub(udev->parent); + int port1 = udev->portnum; + int status; + u16 portchange, portstatus; - /* However we may need to do a reset-resume */ - if (udev->reset_resume) { + status = hub_port_status(hub, port1, &portstatus, &portchange); + status = check_port_resume_type(udev, + hub, port1, status, portchange, portstatus); + + if (status) { + dev_dbg(&udev->dev, "can't resume, status %d\n", status); + hub_port_logical_disconnect(hub, port1); + } else if (udev->reset_resume) { dev_dbg(&udev->dev, "reset-resume\n"); status = usb_reset_device(udev); } -- 2.20.1