upstream/opnsense-src
1
0
Fork 0
mirror of https://github.com/opnsense/src.git synced 2026-06-08 16:22:46 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

MFp4 //depot/projects/usb@157847

Browse source 
Improvements to "usb2_transfer_setup()" and "usb2_transfer_unsetup()". Set
"ppxfer[n]" when the transfer setup is complete to prevent races.  Remove
redundant NULL-checks from "usb2_transfer_unsetup()".

Submitted by:	Hans Petter Selasky
This commit is contained in:
Andrew Thompson 2009-02-24 03:38:24 +00:00
parent 3e5e312a28
commit bce32d7bc4
1 changed files with 69 additions and 71 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

140
sys/dev/usb/usb_transfer.c
View file

@ -887,18 +887,14 @@ usb2_transfer_setup(struct usb2_device *udev,
parm.size[0] += ((-parm.size[0]) & (USB_HOST_ALIGN - 1));
if (buf) {
/*
* Common initialization of the
* "usb2_xfer" structure.
*/
xfer = USB_ADD_BYTES(buf, parm.size[0]);
ppxfer[n] = xfer;
xfer->address = udev->address;
xfer->priv_sc = priv_sc;
xfer->xroot = info;
info->setup_refcount++;
usb2_callout_init_mtx(&xfer->timeout_handle,
&udev->bus->bus_mtx, 0);
@ -915,10 +911,23 @@ usb2_transfer_setup(struct usb2_device *udev,
refcount++;
}
parm.size[0] += sizeof(xfer[0]);
/* set transfer pipe pointer */
xfer->pipe = pipe;
parm.size[0] += sizeof(xfer[0]);
parm.methods = xfer->pipe->methods;
parm.curr_xfer = xfer;
/*
* Call the Host or Device controller transfer
* setup routine:
*/
(udev->bus->methods->xfer_setup) (&parm);
/* check for error */
if (parm.err)
goto done;
if (buf) {
/*
* Increment the pipe refcount. This
@ -930,18 +939,19 @@ usb2_transfer_setup(struct usb2_device *udev,
* want more information.
*/
xfer->pipe->refcount++;
}
parm.methods = xfer->pipe->methods;
parm.curr_xfer = xfer;
/*
* Call the Host or Device controller transfer setup
* routine:
*/
(udev->bus->methods->xfer_setup) (&parm);
/*
* Whenever we set ppxfer[] then we
* also need to increment the
* "setup_refcount":
*/
info->setup_refcount++;
if (parm.err) {
goto done;
/*
* Transfer is successfully setup and
* can be used:
*/
ppxfer[n] = xfer;
}
}
@ -1121,72 +1131,60 @@ usb2_transfer_unsetup(struct usb2_xfer **pxfer, uint16_t n_setup)
while (n_setup--) {
xfer = pxfer[n_setup];
if (xfer) {
if (xfer->pipe) {
USB_XFER_LOCK(xfer);
USB_BUS_LOCK(xfer->xroot->bus);
if (xfer == NULL)
continue;
/*
* HINT: when you start/stop a transfer, it
* might be a good idea to directly use the
* "pxfer[]" structure:
*
* usb2_transfer_start(sc->pxfer[0]);
* usb2_transfer_stop(sc->pxfer[0]);
*
* That way, if your code has many parts that
* will not stop running under the same
* lock, in other words "xfer_mtx", the
* usb2_transfer_start and
* usb2_transfer_stop functions will simply
* return when they detect a NULL pointer
* argument.
*
* To avoid any races we clear the "pxfer[]"
* pointer while holding the private mutex
* of the driver:
*/
pxfer[n_setup] = NULL;
info = xfer->xroot;
USB_BUS_UNLOCK(xfer->xroot->bus);
USB_XFER_UNLOCK(xfer);
USB_XFER_LOCK(xfer);
USB_BUS_LOCK(info->bus);
usb2_transfer_drain(xfer);
/*
* HINT: when you start/stop a transfer, it might be a
* good idea to directly use the "pxfer[]" structure:
*
* usb2_transfer_start(sc->pxfer[0]);
* usb2_transfer_stop(sc->pxfer[0]);
*
* That way, if your code has many parts that will not
* stop running under the same lock, in other words
* "xfer_mtx", the usb2_transfer_start and
* usb2_transfer_stop functions will simply return
* when they detect a NULL pointer argument.
*
* To avoid any races we clear the "pxfer[]" pointer
* while holding the private mutex of the driver:
*/
pxfer[n_setup] = NULL;
if (xfer->flags_int.bdma_enable) {
needs_delay = 1;
}
/*
* NOTE: default pipe does not have an
* interface, even if pipe->iface_index == 0
*/
xfer->pipe->refcount--;
USB_BUS_UNLOCK(info->bus);
USB_XFER_UNLOCK(xfer);
} else {
/* clear the transfer pointer */
pxfer[n_setup] = NULL;
}
usb2_transfer_drain(xfer);
usb2_callout_drain(&xfer->timeout_handle);
if (xfer->flags_int.bdma_enable)
needs_delay = 1;
if (xfer->xroot) {
info = xfer->xroot;
/*
* NOTE: default pipe does not have an
* interface, even if pipe->iface_index == 0
*/
xfer->pipe->refcount--;
USB_BUS_LOCK(info->bus);
usb2_callout_drain(&xfer->timeout_handle);
USB_ASSERT(info->setup_refcount != 0,
("Invalid setup "
"reference count!\n"));
USB_BUS_LOCK(info->bus);
info->setup_refcount--;
USB_ASSERT(info->setup_refcount != 0, ("Invalid setup "
"reference count!\n"));
if (info->setup_refcount == 0) {
usb2_transfer_unsetup_sub(info,
needs_delay);
} else {
USB_BUS_UNLOCK(info->bus);
}
}
info->setup_refcount--;
if (info->setup_refcount == 0) {
usb2_transfer_unsetup_sub(info,
needs_delay);
} else {
USB_BUS_UNLOCK(info->bus);
}
}
}