[PATCH] Staging: quatech_usb2: Convert eos semaphore to mutex

From: Alessio Igor Bogani
Date: Sat May 15 2010 - 17:40:32 EST


The eos semaphore is used as a mutex so replace it with a real mutex.

Signed-off-by: Alessio Igor Bogani <abogani@xxxxxxxxxx>
---
drivers/staging/comedi/drivers/quatech_daqp_cs.c | 15 ++++++++-------
1 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
index 6e9f482..3076666 100644
--- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
+++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
@@ -67,7 +67,7 @@ struct local_info_t {

enum { semaphore, buffer } interrupt_mode;

- struct semaphore eos;
+ struct mutex eos;

struct comedi_device *dev;
struct comedi_subdevice *s;
@@ -238,7 +238,7 @@ static int daqp_ai_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
/* Interrupt handler
*
* Operates in one of two modes. If local->interrupt_mode is
- * 'semaphore', just signal the local->eos semaphore and return
+ * 'semaphore', just signal the local->eos mutex and return
* (one-shot mode). Otherwise (continuous mode), read data in from
* the card, transfer it to the buffer provided by the higher-level
* comedi kernel module, and signal various comedi callback routines,
@@ -287,7 +287,7 @@ static enum irqreturn daqp_interrupt(int irq, void *dev_id)

case semaphore:

- up(&local->eos);
+ mutex_unlock(&local->eos);
break;

case buffer:
@@ -401,8 +401,9 @@ static int daqp_ai_insn_read(struct comedi_device *dev,
return -1;
}

- /* Make sure semaphore is blocked */
- sema_init(&local->eos, 0);
+ mutex_init(&local->eos);
+ /* Make sure mutex is blocked */
+ mutex_lock(&local->eos);
local->interrupt_mode = semaphore;
local->dev = dev;
local->s = s;
@@ -413,9 +414,9 @@ static int daqp_ai_insn_read(struct comedi_device *dev,
outb(DAQP_COMMAND_ARM | DAQP_COMMAND_FIFO_DATA,
dev->iobase + DAQP_COMMAND);

- /* Wait for interrupt service routine to unblock semaphore */
+ /* Wait for interrupt service routine to unblock mutex */
/* Maybe could use a timeout here, but it's interruptible */
- if (down_interruptible(&local->eos))
+ if (mutex_lock_interruptible(&local->eos))
return -EINTR;

data[i] = inb(dev->iobase + DAQP_FIFO);
--
1.7.0.4

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