diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2006-08-11 16:52:39 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-09-27 11:58:54 -0700 |
| commit | d5cbad4b8b37acfde3e63d31b92561b87288ad0f (patch) | |
| tree | 98869f0db85e1f257c5ddd13a2afda934626153a /drivers | |
| parent | 455b25fb209c8241e2163b491228b28667d82c1c (diff) | |
| download | linux-d5cbad4b8b37acfde3e63d31b92561b87288ad0f.tar.gz | |
usbcore: khubd and busy-port handling
We don't want khubd to start interfering in the device-resume process
merely because the PORT_STATUS_C_SUSPEND feature happens to be set.
Ports need to be marked as busy while a resume is taking place.
In addition, so long as ports are marked as busy, khubd won't be able to
clear their various status-change features. On an interrupt-driven root
hub this could lead to an interrupt storm. Root hub IRQs should not be
re-enabled until the busy_bits value is equal to 0.
This patch (as765) fixes these two potential problems.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/core/hub.c | 11 | ||||
| -rw-r--r-- | drivers/usb/core/hub.h | 3 |
2 files changed, 12 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 3924dd080bea23..bdf5be09965068 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1658,6 +1658,8 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev) // dev_dbg(hub->intfdev, "resume port %d\n", port1); + set_bit(port1, hub->busy_bits); + /* see 7.1.7.7; affects power usage, but not budgeting */ status = clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND); @@ -1707,6 +1709,10 @@ hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev) if (status < 0) hub_port_logical_disconnect(hub, port1); + clear_bit(port1, hub->busy_bits); + if (!hub->hdev->parent && !hub->busy_bits[0]) + usb_enable_root_hub_irq(hub->hdev->bus); + return status; } @@ -2690,7 +2696,7 @@ static void hub_events(void) /* If this is a root hub, tell the HCD it's okay to * re-enable port-change interrupts now. */ - if (!hdev->parent) + if (!hdev->parent && !hub->busy_bits[0]) usb_enable_root_hub_irq(hdev->bus); loop: @@ -2865,6 +2871,9 @@ int usb_reset_device(struct usb_device *udev) break; } clear_bit(port1, parent_hub->busy_bits); + if (!parent_hdev->parent && !parent_hub->busy_bits[0]) + usb_enable_root_hub_irq(parent_hdev->bus); + if (ret < 0) goto re_enumerate; diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 29d5f45a845636..0f8e82a4d48067 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -212,7 +212,8 @@ struct usb_hub { unsigned long event_bits[1]; /* status change bitmask */ unsigned long change_bits[1]; /* ports with logical connect status change */ - unsigned long busy_bits[1]; /* ports being reset */ + unsigned long busy_bits[1]; /* ports being reset or + resumed */ #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */ #error event_bits[] is too short! #endif |