Commit a707e953 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman

usb core:

	- initial add of the "int mem_flags" call to the usb_submit_urb() call
parent 040fdeaf
......@@ -1148,6 +1148,7 @@ struct urb * usb_get_urb(struct urb *urb)
/**
* usb_submit_urb - asynchronously issue a transfer request for an endpoint
* @urb: pointer to the urb describing the request
* @mem_flags: the type of memory to allocate, see kmalloc() for a list of valid options for this.
*
* This submits a transfer request, and transfers control of the URB
* describing that request to the USB subsystem. Request completion will
......@@ -1198,11 +1199,48 @@ struct urb * usb_get_urb(struct urb *urb)
* If the USB subsystem can't reserve sufficient bandwidth to perform
* the periodic request, and bandwidth reservation is being done for
* this controller, submitting such a periodic request will fail.
*
* Memory Flags:
*
* General rules for how to decide which mem_flags to use:
*
* Basically the rules are the same as for kmalloc. There are four
* different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and
* GFP_ATOMIC.
*
* GFP_NOFS is not ever used, as it has not been implemented yet.
*
* There are three situations you must use GFP_ATOMIC.
* a) you are inside a completion handler, an interrupt, bottom half,
* tasklet or timer.
* b) you are holding a spinlock or rwlock (does not apply to
* semaphores)
* c) current->state != TASK_RUNNING, this is the case only after
* you've changed it.
*
* GFP_NOIO is used in the block io path and error handling of storage
* devices.
*
* All other situations use GFP_KERNEL.
*
* Specfic rules for how to decide which mem_flags to use:
*
* - start_xmit, timeout, and receive methods of network drivers must
* use GFP_ATOMIC (spinlock)
* - queuecommand methods of scsi drivers must use GFP_ATOMIC (spinlock)
* - If you use a kernel thread with a network driver you must use
* GFP_NOIO, unless b) or c) apply
* - After you have done a down() you use GFP_KERNEL, unless b) or c)
* apply or your are in a storage driver's block io path
* - probe and disconnect use GFP_KERNEL unless b) or c) apply
* - Changing firmware on a running storage or net device uses
* GFP_NOIO, unless b) or c) apply
*
*/
int usb_submit_urb(struct urb *urb)
int usb_submit_urb(struct urb *urb, int mem_flags)
{
if (urb && urb->dev && urb->dev->bus && urb->dev->bus->op)
return urb->dev->bus->op->submit_urb(urb);
return urb->dev->bus->op->submit_urb(urb, mem_flags);
else
return -ENODEV;
}
......@@ -1272,7 +1310,7 @@ static int usb_start_wait_urb(struct urb *urb, int timeout, int* actual_length)
add_wait_queue(&awd.wqh, &wait);
urb->context = &awd;
status = usb_submit_urb(urb);
status = usb_submit_urb(urb, GFP_KERNEL);
if (status) {
// something went wrong
usb_free_urb(urb);
......
......@@ -857,7 +857,7 @@ extern struct urb *usb_alloc_urb(int iso_packets);
extern void usb_free_urb(struct urb *urb);
#define usb_put_urb usb_free_urb
extern struct urb *usb_get_urb(struct urb *urb);
extern int usb_submit_urb(struct urb *urb);
extern int usb_submit_urb(struct urb *urb, int mem_flags);
extern int usb_unlink_urb(struct urb *urb);
/*-------------------------------------------------------------------*
......@@ -906,7 +906,7 @@ struct usb_operations {
int (*allocate)(struct usb_device *);
int (*deallocate)(struct usb_device *);
int (*get_frame_number) (struct usb_device *usb_dev);
int (*submit_urb) (struct urb *urb);
int (*submit_urb) (struct urb *urb, int mem_flags);
int (*unlink_urb) (struct urb *urb);
};
......
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