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Commit f0b11874 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
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patch from Wolfgang Mües <wmues@nexgo.de> for the usb auerswald.c driver: 

  	- Code-Review from Oliver Neukum: remove SMP races.
  	- Added some wake_up calls after auerbuf_releasebuf to wake up tasks waiting
  	  for cp buffers.
  	- Change the module count handling to automatic (owner: THIS_MODULE).
parent 040fdeaf
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Showing with 76 additions and 36 deletions
drivers/usb/auerswald.c
View file @ f0b11874
......@@ -49,7 +49,7 @@ do { \
/*-------------------------------------------------------------------*/
/* Version Information */
#define DRIVER_VERSION "0.9.9"
#define DRIVER_VERSION "0.9.11"
#define DRIVER_AUTHOR "Wolfgang Mes <wmues@nexgo.de>"
#define DRIVER_DESC "Auerswald PBX/System Telephone usb driver"
......@@ -191,6 +191,13 @@ typedef struct auerchain
struct list_head free_list; /* list of available elements */
} auerchain_t,*pauerchain_t;
/* urb blocking completion helper struct */
typedef struct
{
wait_queue_head_t wqh; /* wait for completion */
unsigned int done; /* completion flag */
} auerchain_chs_t,*pauerchain_chs_t;
/* ...................................................................*/
/* buffer element */
struct auerbufctl; /* forward */
......@@ -330,7 +337,7 @@ static void auerchain_complete (struct urb * urb)
urb = acep->urbp;
dbg ("auerchain_complete: submitting next urb from chain");
urb->status = 0; /* needed! */
result = usb_submit_urb( urb);
result = usb_submit_urb(urb, GFP_KERNEL);
/* check for submit errors */
if (result) {
......@@ -408,7 +415,7 @@ static int auerchain_submit_urb_list (pauerchain_t acp, struct urb * urb, int ea
if (acep) {
dbg("submitting urb immediate");
urb->status = 0; /* needed! */
result = usb_submit_urb( urb);
result = usb_submit_urb(urb, GFP_KERNEL);
/* check for submit errors */
if (result) {
urb->status = result;
......@@ -600,8 +607,10 @@ static int auerchain_setup (pauerchain_t acp, unsigned int numElements)
/* completion handler for synchronous chained URBs */
static void auerchain_blocking_completion (struct urb *urb)
{
wait_queue_head_t *wakeup = (wait_queue_head_t *)urb->context;
wake_up (wakeup);
pauerchain_chs_t pchs = (pauerchain_chs_t)urb->context;
pchs->done = 1;
wmb();
wake_up (&pchs->wqh);
}
......@@ -609,36 +618,43 @@ static void auerchain_blocking_completion (struct urb *urb)
static int auerchain_start_wait_urb (pauerchain_t acp, struct urb *urb, int timeout, int* actual_length)
{
DECLARE_WAITQUEUE (wait, current);
DECLARE_WAIT_QUEUE_HEAD (wqh);
auerchain_chs_t chs;
int status;
dbg ("auerchain_start_wait_urb called");
init_waitqueue_head (&wqh);
current->state = TASK_INTERRUPTIBLE;
add_wait_queue (&wqh, &wait);
urb->context = &wqh;
status = auerchain_submit_urb ( acp, urb);
init_waitqueue_head (&chs.wqh);
chs.done = 0;
set_current_state (TASK_UNINTERRUPTIBLE);
add_wait_queue (&chs.wqh, &wait);
urb->context = &chs;
status = auerchain_submit_urb (acp, urb);
if (status) {
/* something went wrong */
current->state = TASK_RUNNING;
remove_wait_queue (&wqh, &wait);
set_current_state (TASK_RUNNING);
remove_wait_queue (&chs.wqh, &wait);
return status;
}
if (urb->status == -EINPROGRESS) {
while (timeout && urb->status == -EINPROGRESS)
status = timeout = schedule_timeout (timeout);
} else
status = 1;
while (timeout && !chs.done)
{
timeout = schedule_timeout (timeout);
set_current_state(TASK_UNINTERRUPTIBLE);
rmb();
}
current->state = TASK_RUNNING;
remove_wait_queue (&wqh, &wait);
set_current_state (TASK_RUNNING);
remove_wait_queue (&chs.wqh, &wait);
if (!status) {
/* timeout */
if (!timeout && !chs.done) {
if (urb->status != -EINPROGRESS) { /* No callback?!! */
dbg ("auerchain_start_wait_urb: raced timeout");
status = urb->status;
} else {
dbg ("auerchain_start_wait_urb: timeout");
auerchain_unlink_urb (acp, urb); /* remove urb safely */
status = -ETIMEDOUT;
}
} else
status = urb->status;
......@@ -932,6 +948,8 @@ static void auerswald_ctrlread_complete (struct urb * urb)
/* reuse the buffer */
err ("control read: transmission error %d, can not retry", urb->status);
auerbuf_releasebuf (bp);
/* Wake up all processes waiting for a buffer */
wake_up (&cp->bufferwait);
return;
}
bp->retries++;
......@@ -1128,7 +1146,7 @@ static int auerswald_int_open (pauerswald_t cp)
FILL_INT_URB (cp->inturbp, cp->usbdev, usb_rcvintpipe (cp->usbdev,AU_IRQENDP), cp->intbufp, irqsize, auerswald_int_complete, cp, ep->bInterval);
/* start the urb */
cp->inturbp->status = 0; /* needed! */
ret = usb_submit_urb (cp->inturbp);
ret = usb_submit_urb (cp->inturbp, GFP_KERNEL);
intoend:
if (ret < 0) {
......@@ -1376,9 +1394,6 @@ static int auerchar_open (struct inode *inode, struct file *file)
}
up (&dev_table_mutex);
/* prevent module unloading */
MOD_INC_USE_COUNT;
/* we have access to the device. Now lets allocate memory */
ccp = (pauerchar_t) kmalloc(sizeof(auerchar_t), GFP_KERNEL);
if (ccp == NULL) {
......@@ -1415,7 +1430,6 @@ static int auerchar_open (struct inode *inode, struct file *file)
/* Error exit */
ofail: up (&cp->mutex);
auerchar_delete (ccp);
MOD_DEC_USE_COUNT;
return ret;
}
......@@ -1568,6 +1582,8 @@ static ssize_t auerchar_read (struct file *file, char *buf, size_t count, loff_t
unsigned long flags;
pauerchar_t ccp = (pauerchar_t) file->private_data;
pauerbuf_t bp = NULL;
wait_queue_t wait;
dbg ("auerchar_read");
/* Error checking */
......@@ -1630,6 +1646,11 @@ static ssize_t auerchar_read (struct file *file, char *buf, size_t count, loff_t
/* a read buffer is not available. Try to get the next data block. */
doreadlist:
/* Preparing for sleep */
init_waitqueue_entry (&wait, current);
set_current_state (TASK_INTERRUPTIBLE);
add_wait_queue (&ccp->readwait, &wait);
bp = NULL;
spin_lock_irqsave (&ccp->bufctl.lock, flags);
if (!list_empty (&ccp->bufctl.rec_buff_list)) {
......@@ -1644,12 +1665,16 @@ static ssize_t auerchar_read (struct file *file, char *buf, size_t count, loff_t
if (bp) {
ccp->readbuf = bp;
ccp->readoffset = AUH_SIZE; /* for headerbyte */
set_current_state (TASK_RUNNING);
remove_wait_queue (&ccp->readwait, &wait);
goto doreadbuf; /* now we can read! */
}
/* no data available. Should we wait? */
if (file->f_flags & O_NONBLOCK) {
dbg ("No read buffer available, returning -EAGAIN");
set_current_state (TASK_RUNNING);
remove_wait_queue (&ccp->readwait, &wait);
up (&ccp->readmutex);
up (&ccp->mutex);
return -EAGAIN; /* nonblocking, no data available */
......@@ -1657,7 +1682,8 @@ static ssize_t auerchar_read (struct file *file, char *buf, size_t count, loff_t
/* yes, we should wait! */
up (&ccp->mutex); /* allow other operations while we wait */
interruptible_sleep_on (&ccp->readwait);
schedule();
remove_wait_queue (&ccp->readwait, &wait);
if (signal_pending (current)) {
/* waked up by a signal */
up (&ccp->readmutex);
......@@ -1688,6 +1714,7 @@ static ssize_t auerchar_write (struct file *file, const char *buf, size_t len, l
pauerbuf_t bp;
unsigned long flags;
int ret;
wait_queue_t wait;
dbg ("auerchar_write %d bytes", len);
......@@ -1724,6 +1751,11 @@ static ssize_t auerchar_write (struct file *file, const char *buf, size_t len, l
up (&ccp->mutex);
return -EIO;
}
/* Prepare for sleep */
init_waitqueue_entry (&wait, current);
set_current_state (TASK_INTERRUPTIBLE);
add_wait_queue (&cp->bufferwait, &wait);
/* Try to get a buffer from the device pool.
We can't use a buffer from ccp->bufctl because the write
command will last beond a release() */
......@@ -1744,16 +1776,22 @@ static ssize_t auerchar_write (struct file *file, const char *buf, size_t len, l
/* NONBLOCK: don't wait */
if (file->f_flags & O_NONBLOCK) {
set_current_state (TASK_RUNNING);
remove_wait_queue (&cp->bufferwait, &wait);
return -EAGAIN;
}
/* BLOCKING: wait */
interruptible_sleep_on (&cp->bufferwait);
schedule();
remove_wait_queue (&cp->bufferwait, &wait);
if (signal_pending (current)) {
/* waked up by a signal */
return -ERESTARTSYS;
}
goto write_again;
} else {
set_current_state (TASK_RUNNING);
remove_wait_queue (&cp->bufferwait, &wait);
}
/* protect against too big write requests */
......@@ -1763,6 +1801,8 @@ static ssize_t auerchar_write (struct file *file, const char *buf, size_t len, l
if (copy_from_user ( bp->bufp+AUH_SIZE, buf, len)) {
dbg ("copy_from_user failed");
auerbuf_releasebuf (bp);
/* Wake up all processes waiting for a buffer */
wake_up (&cp->bufferwait);
up (&cp->mutex);
up (&ccp->mutex);
return -EIO;
......@@ -1787,6 +1827,8 @@ static ssize_t auerchar_write (struct file *file, const char *buf, size_t len, l
if (ret) {
dbg ("auerchar_write: nonzero result of auerchain_submit_urb %d", ret);
auerbuf_releasebuf (bp);
/* Wake up all processes waiting for a buffer */
wake_up (&cp->bufferwait);
up (&ccp->mutex);
return -EIO;
}
......@@ -1831,9 +1873,6 @@ static int auerchar_release (struct inode *inode, struct file *file)
up (&ccp->mutex);
auerchar_delete (ccp);
/* release the module */
MOD_DEC_USE_COUNT;
return 0;
}
......@@ -2154,3 +2193,4 @@ module_init (auerswald_init);
module_exit (auerswald_cleanup);
/* --------------------------------------------------------------------- */
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