staging: comedi: ni_660x: add comments for the spinlock_t definitions

Fix the checkpatch.pl issues:

CHECK: spinlock_t definition without comment

For aesthetics, rename the 'soft_reg_copy_lock' to clarify what it's
used for.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/ni_660x.c b/drivers/staging/comedi/drivers/ni_660x.c
index 3edea9928b09c0029d9b2d924d0118305c538ac3..2926d265f0bdf0ada57ddcd1ec79c074d2ef9534 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_660x.c
+++ b/drivers/staging/comedi/drivers/ni_660x.c
@@ -398,11 +398,13 @@ struct ni_660x_private {
        struct ni_gpct_device *counter_dev;
        struct mite_dma_descriptor_ring
        *mite_rings[NI_660X_MAX_NUM_CHIPS][counters_per_chip];
+       /* protects mite channel request/release */
        spinlock_t mite_channel_lock;
-       /* interrupt_lock prevents races between interrupt and comedi_poll */
+       /* prevents races between interrupt and comedi_poll */
        spinlock_t interrupt_lock;
+       /* protects dma_cfg changes */
+       spinlock_t dma_cfg_lock;
        unsigned int dma_cfg[NI_660X_MAX_NUM_CHIPS];
-       spinlock_t soft_reg_copy_lock;
        unsigned int io_cfg[NUM_PFI_CHANNELS];
        u64 io_dir;
 };
@@ -482,7 +484,7 @@ static inline void ni_660x_set_dma_channel(struct comedi_device *dev,
        unsigned int chip = counter->chip_index;
        unsigned long flags;
 
-       spin_lock_irqsave(&devpriv->soft_reg_copy_lock, flags);
+       spin_lock_irqsave(&devpriv->dma_cfg_lock, flags);
        devpriv->dma_cfg[chip] &= ~NI660X_DMA_CFG_SEL_MASK(mite_channel);
        devpriv->dma_cfg[chip] |= NI660X_DMA_CFG_SEL(mite_channel,
                                                     counter->counter_index);
@@ -490,7 +492,7 @@ static inline void ni_660x_set_dma_channel(struct comedi_device *dev,
                      NI660X_DMA_CFG_RESET(mite_channel),
                      NI660X_DMA_CFG);
        mmiowb();
-       spin_unlock_irqrestore(&devpriv->soft_reg_copy_lock, flags);
+       spin_unlock_irqrestore(&devpriv->dma_cfg_lock, flags);
 }
 
 static inline void ni_660x_unset_dma_channel(struct comedi_device *dev,
@@ -501,12 +503,12 @@ static inline void ni_660x_unset_dma_channel(struct comedi_device *dev,
        unsigned int chip = counter->chip_index;
        unsigned long flags;
 
-       spin_lock_irqsave(&devpriv->soft_reg_copy_lock, flags);
+       spin_lock_irqsave(&devpriv->dma_cfg_lock, flags);
        devpriv->dma_cfg[chip] &= ~NI660X_DMA_CFG_SEL_MASK(mite_channel);
        devpriv->dma_cfg[chip] |= NI660X_DMA_CFG_SEL_NONE(mite_channel);
        ni_660x_write(dev, chip, devpriv->dma_cfg[chip], NI660X_DMA_CFG);
        mmiowb();
-       spin_unlock_irqrestore(&devpriv->soft_reg_copy_lock, flags);
+       spin_unlock_irqrestore(&devpriv->dma_cfg_lock, flags);
 }
 
 static int ni_660x_request_mite_channel(struct comedi_device *dev,
@@ -662,7 +664,7 @@ static int ni_660x_allocate_private(struct comedi_device *dev)
 
        spin_lock_init(&devpriv->mite_channel_lock);
        spin_lock_init(&devpriv->interrupt_lock);
-       spin_lock_init(&devpriv->soft_reg_copy_lock);
+       spin_lock_init(&devpriv->dma_cfg_lock);
        for (i = 0; i < NUM_PFI_CHANNELS; ++i)
                devpriv->io_cfg[i] = NI_660X_PFI_OUTPUT_COUNTER;