dma: timb-dma: Update comment and fix compiler warning

An incremental patch which clarifies what the spinlock is used for
and fixes a compiler warning.

Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dma/timb_dma.c b/drivers/dma/timb_dma.c
index 4dd7102..145f1c2 100644 (file)
--- a/drivers/dma/timb_dma.c
+++ b/drivers/dma/timb_dma.c
@@ -79,7 +79,10 @@ struct timb_dma_desc {
 struct timb_dma_chan {
        struct dma_chan         chan;
        void __iomem            *membase;
-       spinlock_t              lock; /* Used for mutual exclusion */
+       spinlock_t              lock; /* Used to protect data structures,
+                                       especially the lists and descriptors,
+                                       from races between the tasklet and calls
+                                       from above */
        dma_cookie_t            last_completed_cookie;
        bool                    ongoing;
        struct list_head        active_list;
@@ -197,7 +200,7 @@ static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
        }
 
        dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: %p\n",
-               dma_desc, (void *)(int)sg_dma_address(sg));
+               dma_desc, (void *)sg_dma_address(sg));
 
        dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
        dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;