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author | Alan Stern <stern@rowland.harvard.edu> | 2009-06-29 14:43:32 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-07-12 22:16:38 (GMT) |
commit | cb88a1b887bb8908f6e00ce29e893ea52b074940 (patch) | |
tree | 198cba7974836d994cfc839b95242e8321702d5c /drivers/usb/core | |
parent | 87ea8c887905d8b13ae90b537117592ed027632a (diff) | |
download | linux-cb88a1b887bb8908f6e00ce29e893ea52b074940.tar.xz |
USB: fix the clear_tt_buffer interface
This patch (as1255) updates the interface for calling
usb_hub_clear_tt_buffer(). Even the name of the function is changed!
When an async URB (i.e., Control or Bulk) going through a high-speed
hub to a non-high-speed device is cancelled or fails, the hub's
Transaction Translator buffer may be left busy still trying to
complete the transaction. The buffer has to be cleared; that's what
usb_hub_clear_tt_buffer() does.
It isn't safe to send any more URBs to the same endpoint until the TT
buffer is fully clear. Therefore the HCD needs to be told when the
Clear-TT-Buffer request has finished. This patch adds a callback
method to struct hc_driver for that purpose, and makes the hub driver
invoke the callback at the proper time.
The patch also changes a couple of names; "hub_tt_kevent" and
"tt.kevent" now look rather antiquated.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r-- | drivers/usb/core/hcd.h | 4 | ||||
-rw-r--r-- | drivers/usb/core/hub.c | 40 | ||||
-rw-r--r-- | drivers/usb/core/hub.h | 6 |
3 files changed, 34 insertions, 16 deletions
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h index d397ecf..ec5c67e 100644 --- a/drivers/usb/core/hcd.h +++ b/drivers/usb/core/hcd.h @@ -227,6 +227,10 @@ struct hc_driver { /* has a port been handed over to a companion? */ int (*port_handed_over)(struct usb_hcd *, int); + /* CLEAR_TT_BUFFER completion callback */ + void (*clear_tt_buffer_complete)(struct usb_hcd *, + struct usb_host_endpoint *); + /* xHCI specific functions */ /* Called by usb_alloc_dev to alloc HC device structures */ int (*alloc_dev)(struct usb_hcd *, struct usb_device *); diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 2af3b4f..71f86c6 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -450,10 +450,10 @@ hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt) * talking to TTs must queue control transfers (not just bulk and iso), so * both can talk to the same hub concurrently. */ -static void hub_tt_kevent (struct work_struct *work) +static void hub_tt_work(struct work_struct *work) { struct usb_hub *hub = - container_of(work, struct usb_hub, tt.kevent); + container_of(work, struct usb_hub, tt.clear_work); unsigned long flags; int limit = 100; @@ -462,6 +462,7 @@ static void hub_tt_kevent (struct work_struct *work) struct list_head *next; struct usb_tt_clear *clear; struct usb_device *hdev = hub->hdev; + const struct hc_driver *drv; int status; next = hub->tt.clear_list.next; @@ -471,21 +472,25 @@ static void hub_tt_kevent (struct work_struct *work) /* drop lock so HCD can concurrently report other TT errors */ spin_unlock_irqrestore (&hub->tt.lock, flags); status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt); - spin_lock_irqsave (&hub->tt.lock, flags); - if (status) dev_err (&hdev->dev, "clear tt %d (%04x) error %d\n", clear->tt, clear->devinfo, status); + + /* Tell the HCD, even if the operation failed */ + drv = clear->hcd->driver; + if (drv->clear_tt_buffer_complete) + (drv->clear_tt_buffer_complete)(clear->hcd, clear->ep); + kfree(clear); + spin_lock_irqsave(&hub->tt.lock, flags); } spin_unlock_irqrestore (&hub->tt.lock, flags); } /** - * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub - * @udev: the device whose split transaction failed - * @pipe: identifies the endpoint of the failed transaction + * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub + * @urb: an URB associated with the failed or incomplete split transaction * * High speed HCDs use this to tell the hub driver that some split control or * bulk transaction failed in a way that requires clearing internal state of @@ -495,8 +500,10 @@ static void hub_tt_kevent (struct work_struct *work) * It may not be possible for that hub to handle additional full (or low) * speed transactions until that state is fully cleared out. */ -void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe) +int usb_hub_clear_tt_buffer(struct urb *urb) { + struct usb_device *udev = urb->dev; + int pipe = urb->pipe; struct usb_tt *tt = udev->tt; unsigned long flags; struct usb_tt_clear *clear; @@ -508,7 +515,7 @@ void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe) if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) { dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n"); /* FIXME recover somehow ... RESET_TT? */ - return; + return -ENOMEM; } /* info that CLEAR_TT_BUFFER needs */ @@ -520,14 +527,19 @@ void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe) : (USB_ENDPOINT_XFER_BULK << 11); if (usb_pipein (pipe)) clear->devinfo |= 1 << 15; - + + /* info for completion callback */ + clear->hcd = bus_to_hcd(udev->bus); + clear->ep = urb->ep; + /* tell keventd to clear state for this TT */ spin_lock_irqsave (&tt->lock, flags); list_add_tail (&clear->clear_list, &tt->clear_list); - schedule_work (&tt->kevent); + schedule_work(&tt->clear_work); spin_unlock_irqrestore (&tt->lock, flags); + return 0; } -EXPORT_SYMBOL_GPL(usb_hub_tt_clear_buffer); +EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer); /* If do_delay is false, return the number of milliseconds the caller * needs to delay. @@ -818,7 +830,7 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type) if (hub->has_indicators) cancel_delayed_work_sync(&hub->leds); if (hub->tt.hub) - cancel_work_sync(&hub->tt.kevent); + cancel_work_sync(&hub->tt.clear_work); } /* caller has locked the hub device */ @@ -935,7 +947,7 @@ static int hub_configure(struct usb_hub *hub, spin_lock_init (&hub->tt.lock); INIT_LIST_HEAD (&hub->tt.clear_list); - INIT_WORK (&hub->tt.kevent, hub_tt_kevent); + INIT_WORK(&hub->tt.clear_work, hub_tt_work); switch (hdev->descriptor.bDeviceProtocol) { case 0: break; diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 889c0f3..de8081f 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -188,16 +188,18 @@ struct usb_tt { /* for control/bulk error recovery (CLEAR_TT_BUFFER) */ spinlock_t lock; struct list_head clear_list; /* of usb_tt_clear */ - struct work_struct kevent; + struct work_struct clear_work; }; struct usb_tt_clear { struct list_head clear_list; unsigned tt; u16 devinfo; + struct usb_hcd *hcd; + struct usb_host_endpoint *ep; }; -extern void usb_hub_tt_clear_buffer(struct usb_device *dev, int pipe); +extern int usb_hub_clear_tt_buffer(struct urb *urb); extern void usb_ep0_reinit(struct usb_device *); #endif /* __LINUX_HUB_H */ |