linux-kernel - [PATCH v2 2/3] media: ngene: Replace semaphore stream

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Date:   Tue, 13 Jun 2017 14:28:49 +0530
From:   Binoy Jayan <binoy.jayan@...aro.org>
To:     Binoy Jayan <binoy.jayan@...aro.org>
Cc:     linux-kernel@...r.kernel.org, Arnd Bergmann <arnd@...db.de>,
        Rajendra <rnayak@...eaurora.org>,
        Mark Brown <broonie@...nel.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Julia Lawall <Julia.Lawall@...6.fr>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Cao jin <caoj.fnst@...fujitsu.com>, linux-media@...r.kernel.org
Subject: [PATCH v2 2/3] media: ngene: Replace semaphore stream_mutex with mutex

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@...aro.org>
---
 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