[PATCH v2 2/3] media: ngene: Replace semaphore stream_mutex with mutex

From: Binoy Jayan
Date: Tue Jun 13 2017 - 04:59:10 EST


The semaphore 'stream_mutex' is used as a simple mutex, so
it should be written as one. Also moving the mutex_[lock/unlock]
to the caller as it is anyway locked at the beginning of the
callee thus avoiding repetition.

Signed-off-by: Binoy Jayan <binoy.jayan@xxxxxxxxxx>
---
drivers/media/pci/ngene/ngene-core.c | 18 +++++++-----------
drivers/media/pci/ngene/ngene.h | 2 +-
2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/media/pci/ngene/ngene-core.c b/drivers/media/pci/ngene/ngene-core.c
index eeb61eb..ea64901 100644
--- a/drivers/media/pci/ngene/ngene-core.c
+++ b/drivers/media/pci/ngene/ngene-core.c
@@ -560,7 +560,6 @@ static int ngene_command_stream_control(struct ngene *dev, u8 stream,
u16 BsSPI = ((stream & 1) ? 0x9800 : 0x9700);
u16 BsSDO = 0x9B00;

- down(&dev->stream_mutex);
memset(&com, 0, sizeof(com));
com.cmd.hdr.Opcode = CMD_CONTROL;
com.cmd.hdr.Length = sizeof(struct FW_STREAM_CONTROL) - 2;
@@ -586,17 +585,13 @@ static int ngene_command_stream_control(struct ngene *dev, u8 stream,
chan->State = KSSTATE_ACQUIRE;
chan->HWState = HWSTATE_STOP;
spin_unlock_irq(&chan->state_lock);
- if (ngene_command(dev, &com) < 0) {
- up(&dev->stream_mutex);
+ if (ngene_command(dev, &com) < 0)
return -1;
- }
/* clear_buffers(chan); */
flush_buffers(chan);
- up(&dev->stream_mutex);
return 0;
}
spin_unlock_irq(&chan->state_lock);
- up(&dev->stream_mutex);
return 0;
}

@@ -692,11 +687,9 @@ static int ngene_command_stream_control(struct ngene *dev, u8 stream,
chan->HWState = HWSTATE_STARTUP;
spin_unlock_irq(&chan->state_lock);

- if (ngene_command(dev, &com) < 0) {
- up(&dev->stream_mutex);
+ if (ngene_command(dev, &com) < 0)
return -1;
- }
- up(&dev->stream_mutex);
+
return 0;
}

@@ -750,8 +743,11 @@ void set_transfer(struct ngene_channel *chan, int state)
/* else printk(KERN_INFO DEVICE_NAME ": lock=%08x\n",
ngreadl(0x9310)); */

+ mutex_lock(&dev->stream_mutex);
ret = ngene_command_stream_control(dev, chan->number,
control, mode, flags);
+ mutex_unlock(&dev->stream_mutex);
+
if (!ret)
chan->running = state;
else
@@ -1347,7 +1343,7 @@ static int ngene_start(struct ngene *dev)
init_waitqueue_head(&dev->tx_wq);
init_waitqueue_head(&dev->rx_wq);
mutex_init(&dev->cmd_mutex);
- sema_init(&dev->stream_mutex, 1);
+ mutex_init(&dev->stream_mutex);
sema_init(&dev->pll_mutex, 1);
sema_init(&dev->i2c_switch_mutex, 1);
spin_lock_init(&dev->cmd_lock);
diff --git a/drivers/media/pci/ngene/ngene.h b/drivers/media/pci/ngene/ngene.h
index e600b70..0dd15d6 100644
--- a/drivers/media/pci/ngene/ngene.h
+++ b/drivers/media/pci/ngene/ngene.h
@@ -763,7 +763,7 @@ struct ngene {
wait_queue_head_t cmd_wq;
int cmd_done;
struct mutex cmd_mutex;
- struct semaphore stream_mutex;
+ struct mutex stream_mutex;
struct semaphore pll_mutex;
struct semaphore i2c_switch_mutex;
int i2c_current_channel;
--
Binoy Jayan