From 584c5b7cf06194464240280483ee0376cdddbbae Mon Sep 17 00:00:00 2001 From: Max Vozeler Date: Tue, 21 Sep 2010 17:43:30 +0200 Subject: [PATCH] staging: usbip: Process event flags without delay The way the event handler works can cause it to delay events until eventual wakeup for another event. For example, on device detach (vhci): - Write to sysfs detach file -> usbip_event_add(VDEV_EVENT_DOWN) -> wakeup() #define VDEV_EVENT_DOWN (USBIP_EH_SHUTDOWN | USBIP_EH_RESET). - Event thread wakes up and passes the event to event_handler() to process. - It processes and clears the USBIP_EH_SHUTDOWN flag then returns. - The outer event loop (event_handler_loop()) calls wait_event_interruptible(). The processing of the second flag which is part of VDEV_EVENT_DOWN (USBIP_EH_RESET) did not happen yet. It is delayed until the next event. This means the ->reset callback may not happen for a long time (if ever), leaving the usbip port in a weird state which prevents its reuse. This patch changes the handler to process all flags before waiting for another wakeup. I have verified this change to fix a problem which prevented reattach of a usbip device. It also helps for socket errors which missed the RESET as well. The delayed event processing also affects the stub side of usbip and the error handling there. Signed-off-by: Max Vozeler Reported-by: Marco Lancione Tested-by: Luc Jalbert Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/staging/usbip/usbip_event.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/drivers/staging/usbip/usbip_event.c b/drivers/staging/usbip/usbip_event.c index a2566f1..af3832b 100644 --- a/drivers/staging/usbip/usbip_event.c +++ b/drivers/staging/usbip/usbip_event.c @@ -38,21 +38,13 @@ static int event_handler(struct usbip_device *ud) ud->eh_ops.shutdown(ud); ud->event &= ~USBIP_EH_SHUTDOWN; - - break; } - /* Stop the error handler. */ - if (ud->event & USBIP_EH_BYE) - return -1; - /* Reset the device. */ if (ud->event & USBIP_EH_RESET) { ud->eh_ops.reset(ud); ud->event &= ~USBIP_EH_RESET; - - break; } /* Mark the device as unusable. */ @@ -60,13 +52,11 @@ static int event_handler(struct usbip_device *ud) ud->eh_ops.unusable(ud); ud->event &= ~USBIP_EH_UNUSABLE; - - break; } - /* NOTREACHED */ - printk(KERN_ERR "%s: unknown event\n", __func__); - return -1; + /* Stop the error handler. */ + if (ud->event & USBIP_EH_BYE) + return -1; } return 0; -- 2.7.4