From: Alan Stern Date: Mon, 28 Apr 2008 15:06:42 +0000 (-0400) Subject: USB: simplify hub_restart() logic X-Git-Tag: v2.6.27-rc1~946^2~90 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=6ee0b270c733027b2b716b1c80b9aced41e08d20;p=linux-2.6-omap-h63xx.git USB: simplify hub_restart() logic This patch (as1081) straightens out the logic of the hub_restart() routine. Each port of the hub is scanned and the driver makes sure that ports which are supposed to be disabled really _are_ disabled. Any ports with a significant change in status are flagged in hub->change_bits, so that khubd can focus on them without the need to scan all the ports a second time -- which means the hub->activating flag is no longer needed. Also, it is now recognized explicitly that the only reason for resuming a port which was not suspended is to carry out a reset-resume operation, which happens only in a non-CONFIG_USB_SUSPEND setting. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index d0b37d776af..bf1585b203c 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -805,8 +805,6 @@ static int usb_resume_device(struct usb_device *udev) if (udev->state == USB_STATE_NOTATTACHED) goto done; - if (udev->state != USB_STATE_SUSPENDED && !udev->reset_resume) - goto done; /* Can't resume it if it doesn't have a driver. */ if (udev->dev.driver == NULL) { @@ -1173,11 +1171,8 @@ static int usb_resume_both(struct usb_device *udev) * then we're stuck. */ status = usb_resume_device(udev); } - } else { - - /* Needed for reset-resume */ + } else if (udev->reset_resume) status = usb_resume_device(udev); - } if (status == 0 && udev->actconfig) { for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 976da1c4919..054a76dc5d5 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -72,7 +72,6 @@ struct usb_hub { unsigned limited_power:1; unsigned quiescing:1; - unsigned activating:1; unsigned disconnected:1; unsigned has_indicators:1; @@ -539,7 +538,6 @@ static void hub_quiesce(struct usb_hub *hub) { /* (nonblocking) khubd and related activity won't re-trigger */ hub->quiescing = 1; - hub->activating = 0; /* (blocking) stop khubd and related activity */ usb_kill_urb(hub->urb); @@ -554,7 +552,6 @@ static void hub_activate(struct usb_hub *hub) int status; hub->quiescing = 0; - hub->activating = 1; status = usb_submit_urb(hub->urb, GFP_NOIO); if (status < 0) @@ -638,81 +635,83 @@ static void hub_stop(struct usb_hub *hub) hub_quiesce(hub); } -#define HUB_RESET 1 -#define HUB_RESUME 2 -#define HUB_RESET_RESUME 3 - -#ifdef CONFIG_PM +enum hub_activation_type { + HUB_INIT, HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME +}; -static void hub_restart(struct usb_hub *hub, int type) +static void hub_restart(struct usb_hub *hub, enum hub_activation_type type) { struct usb_device *hdev = hub->hdev; int port1; - /* Check each of the children to see if they require - * USB-PERSIST handling or disconnection. Also check - * each unoccupied port to make sure it is still disabled. + /* Check each port and set hub->change_bits to let khubd know + * which ports need attention. */ for (port1 = 1; port1 <= hdev->maxchild; ++port1) { struct usb_device *udev = hdev->children[port1-1]; - int status = 0; + int status; u16 portstatus, portchange; - if (!udev || udev->state == USB_STATE_NOTATTACHED) { - if (type != HUB_RESET) { - status = hub_port_status(hub, port1, - &portstatus, &portchange); - if (status == 0 && (portstatus & - USB_PORT_STAT_ENABLE)) - clear_port_feature(hdev, port1, - USB_PORT_FEAT_ENABLE); - } - continue; + portstatus = portchange = 0; + status = hub_port_status(hub, port1, &portstatus, &portchange); + if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) + dev_dbg(hub->intfdev, + "port %d: status %04x change %04x\n", + port1, portstatus, portchange); + + /* After anything other than HUB_RESUME (i.e., initialization + * or any sort of reset), every port should be disabled. + * Unconnected ports should likewise be disabled (paranoia), + * and so should ports for which we have no usb_device. + */ + if ((portstatus & USB_PORT_STAT_ENABLE) && ( + type != HUB_RESUME || + !(portstatus & USB_PORT_STAT_CONNECTION) || + !udev || + udev->state == USB_STATE_NOTATTACHED)) { + clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE); + portstatus &= ~USB_PORT_STAT_ENABLE; } - /* Was the power session lost while we were suspended? */ - switch (type) { - case HUB_RESET_RESUME: - portstatus = 0; - portchange = USB_PORT_STAT_C_CONNECTION; - break; - - case HUB_RESET: - case HUB_RESUME: - status = hub_port_status(hub, port1, - &portstatus, &portchange); - break; - } + if (!udev || udev->state == USB_STATE_NOTATTACHED) { + /* Tell khubd to disconnect the device or + * check for a new connection + */ + if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) + set_bit(port1, hub->change_bits); + + } else if (portstatus & USB_PORT_STAT_ENABLE) { + /* The power session apparently survived the resume. + * If there was an overcurrent or suspend change + * (i.e., remote wakeup request), have khubd + * take care of it. + */ + if (portchange) + set_bit(port1, hub->change_bits); - /* For "USB_PERSIST"-enabled children we must - * mark the child device for reset-resume and - * turn off the various status changes to prevent - * khubd from disconnecting it later. - */ - if (udev->persist_enabled && status == 0 && - !(portstatus & USB_PORT_STAT_ENABLE)) { + } else if (udev->persist_enabled) { + /* Turn off the status changes to prevent khubd + * from disconnecting the device. + */ if (portchange & USB_PORT_STAT_C_ENABLE) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_ENABLE); if (portchange & USB_PORT_STAT_C_CONNECTION) clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_C_CONNECTION); +#ifdef CONFIG_PM udev->reset_resume = 1; +#endif + } else { + /* The power session is gone; tell khubd */ + usb_set_device_state(udev, USB_STATE_NOTATTACHED); + set_bit(port1, hub->change_bits); } - - /* Otherwise for a reset_resume we must disconnect the child, - * but as we may not lock the child device here - * we have to do a "logical" disconnect. - */ - else if (type == HUB_RESET_RESUME) - hub_port_logical_disconnect(hub, port1); } hub_activate(hub); } -#endif /* CONFIG_PM */ - /* caller has locked the hub device */ static int hub_pre_reset(struct usb_interface *intf) { @@ -728,7 +727,7 @@ static int hub_post_reset(struct usb_interface *intf) struct usb_hub *hub = usb_get_intfdata(intf); hub_power_on(hub); - hub_activate(hub); + hub_restart(hub, HUB_POST_RESET); return 0; } @@ -2903,7 +2902,7 @@ static void hub_events(void) continue; connect_change = test_bit(i, hub->change_bits); if (!test_and_clear_bit(i, hub->event_bits) && - !connect_change && !hub->activating) + !connect_change) continue; ret = hub_port_status(hub, i, @@ -2911,11 +2910,6 @@ static void hub_events(void) if (ret < 0) continue; - if (hub->activating && !hdev->children[i-1] && - (portstatus & - USB_PORT_STAT_CONNECTION)) - connect_change = 1; - if (portchange & USB_PORT_STAT_C_CONNECTION) { clear_port_feature(hdev, i, USB_PORT_FEAT_C_CONNECTION); @@ -3011,8 +3005,6 @@ static void hub_events(void) } } - hub->activating = 0; - /* If this is a root hub, tell the HCD it's okay to * re-enable port-change interrupts now. */ if (!hdev->parent && !hub->busy_bits[0])