From 5257d97a219e17abf8188f136e1189da3b3af33c Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 22 Sep 2008 14:43:08 -0400 Subject: [PATCH] USB: revert recovery from transient errors This patch (as1135) essentially reverts the major parts of two earlier patches to usbcore, because they ended up causing a regression. Trying to recover from transient communication errors can lead to other problems, because operations that failed during the error period are not always retried. The simplest example is the initial Set-Config request sent after device enumeration; if it gets lost then it will not be retried and the device will remain unconfigured. This patch restores the old behavior in which any port disconnect or port disable causes the entire device structure to be removed, fixing a reported regression. Signed-off-by: Alan Stern Tested-by: Frans Pop Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 39 +++++++++++++++++---------------------- 1 file changed, 17 insertions(+), 22 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6a5cb018383d..d99963873e37 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2683,35 +2683,17 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, USB_PORT_STAT_C_ENABLE); #endif - /* Try to use the debounce delay for protection against - * port-enable changes caused, for example, by EMI. - */ - if (portchange & (USB_PORT_STAT_C_CONNECTION | - USB_PORT_STAT_C_ENABLE)) { - status = hub_port_debounce(hub, port1); - if (status < 0) { - if (printk_ratelimit()) - dev_err (hub_dev, "connect-debounce failed, " - "port %d disabled\n", port1); - portstatus &= ~USB_PORT_STAT_CONNECTION; - } else { - portstatus = status; - } - } - /* Try to resuscitate an existing device */ udev = hdev->children[port1-1]; if ((portstatus & USB_PORT_STAT_CONNECTION) && udev && udev->state != USB_STATE_NOTATTACHED) { - usb_lock_device(udev); if (portstatus & USB_PORT_STAT_ENABLE) { status = 0; /* Nothing to do */ - } else if (!udev->persist_enabled) { - status = -ENODEV; /* Mustn't resuscitate */ #ifdef CONFIG_USB_SUSPEND - } else if (udev->state == USB_STATE_SUSPENDED) { + } else if (udev->state == USB_STATE_SUSPENDED && + udev->persist_enabled) { /* For a suspended device, treat this as a * remote wakeup event. */ @@ -2726,7 +2708,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, #endif } else { - status = usb_reset_device(udev); + status = -ENODEV; /* Don't resuscitate */ } usb_unlock_device(udev); @@ -2741,6 +2723,19 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, usb_disconnect(&hdev->children[port1-1]); clear_bit(port1, hub->change_bits); + if (portchange & (USB_PORT_STAT_C_CONNECTION | + USB_PORT_STAT_C_ENABLE)) { + status = hub_port_debounce(hub, port1); + if (status < 0) { + if (printk_ratelimit()) + dev_err(hub_dev, "connect-debounce failed, " + "port %d disabled\n", port1); + portstatus &= ~USB_PORT_STAT_CONNECTION; + } else { + portstatus = status; + } + } + /* Return now if debouncing failed or nothing is connected */ if (!(portstatus & USB_PORT_STAT_CONNECTION)) { @@ -2748,7 +2743,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2 && !(portstatus & (1 << USB_PORT_FEAT_POWER))) set_port_feature(hdev, port1, USB_PORT_FEAT_POWER); - + if (portstatus & USB_PORT_STAT_ENABLE) goto done; return; -- 2.11.0