MIPS: Alchemy: Simplify DMA channel allocation code.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>

diff --git a/arch/mips/alchemy/common/dbdma.c b/arch/mips/alchemy/common/dbdma.c
index 493e570..99ae84c 100644 (file)
--- a/arch/mips/alchemy/common/dbdma.c
+++ b/arch/mips/alchemy/common/dbdma.c
@@ -237,7 +237,7 @@ u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid,
        void (*callback)(int, void *), void *callparam)
 {
        unsigned long   flags;
-       u32             used, chan, rv;
+       u32             used, chan;
        u32             dcp;
        int             i;
        dbdev_tab_t     *stp, *dtp;
@@ -260,7 +260,6 @@ u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid,
                return 0;
 
        used = 0;
-       rv = 0;
 
        /* Check to see if we can get both channels. */
        spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
@@ -281,63 +280,65 @@ u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid,
                used++;
        spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
 
-       if (!used) {
-               /* Let's see if we can allocate a channel for it. */
-               ctp = NULL;
-               chan = 0;
-               spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
-               for (i = 0; i < NUM_DBDMA_CHANS; i++)
-                       if (chan_tab_ptr[i] == NULL) {
-                               /*
-                                * If kmalloc fails, it is caught below same
-                                * as a channel not available.
-                                */
-                               ctp = kmalloc(sizeof(chan_tab_t), GFP_ATOMIC);
-                               chan_tab_ptr[i] = ctp;
-                               break;
-                       }
-               spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
-
-               if (ctp != NULL) {
-                       memset(ctp, 0, sizeof(chan_tab_t));
-                       ctp->chan_index = chan = i;
-                       dcp = DDMA_CHANNEL_BASE;
-                       dcp += (0x0100 * chan);
-                       ctp->chan_ptr = (au1x_dma_chan_t *)dcp;
-                       cp = (au1x_dma_chan_t *)dcp;
-                       ctp->chan_src = stp;
-                       ctp->chan_dest = dtp;
-                       ctp->chan_callback = callback;
-                       ctp->chan_callparam = callparam;
-
-                       /* Initialize channel configuration. */
-                       i = 0;
-                       if (stp->dev_intlevel)
-                               i |= DDMA_CFG_SED;
-                       if (stp->dev_intpolarity)
-                               i |= DDMA_CFG_SP;
-                       if (dtp->dev_intlevel)
-                               i |= DDMA_CFG_DED;
-                       if (dtp->dev_intpolarity)
-                               i |= DDMA_CFG_DP;
-                       if ((stp->dev_flags & DEV_FLAGS_SYNC) ||
-                               (dtp->dev_flags & DEV_FLAGS_SYNC))
-                                       i |= DDMA_CFG_SYNC;
-                       cp->ddma_cfg = i;
-                       au_sync();
+       if (used)
+               return 0;
 
-                       /* Return a non-zero value that can be used to
-                        * find the channel information in subsequent
-                        * operations.
+       /* Let's see if we can allocate a channel for it. */
+       ctp = NULL;
+       chan = 0;
+       spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
+       for (i = 0; i < NUM_DBDMA_CHANS; i++)
+               if (chan_tab_ptr[i] == NULL) {
+                       /*
+                        * If kmalloc fails, it is caught below same
+                        * as a channel not available.
                         */
-                       rv = (u32)(&chan_tab_ptr[chan]);
-               } else {
-                       /* Release devices */
-                       stp->dev_flags &= ~DEV_FLAGS_INUSE;
-                       dtp->dev_flags &= ~DEV_FLAGS_INUSE;
+                       ctp = kmalloc(sizeof(chan_tab_t), GFP_ATOMIC);
+                       chan_tab_ptr[i] = ctp;
+                       break;
                }
+       spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
+
+       if (ctp != NULL) {
+               memset(ctp, 0, sizeof(chan_tab_t));
+               ctp->chan_index = chan = i;
+               dcp = DDMA_CHANNEL_BASE;
+               dcp += (0x0100 * chan);
+               ctp->chan_ptr = (au1x_dma_chan_t *)dcp;
+               cp = (au1x_dma_chan_t *)dcp;
+               ctp->chan_src = stp;
+               ctp->chan_dest = dtp;
+               ctp->chan_callback = callback;
+               ctp->chan_callparam = callparam;
+
+               /* Initialize channel configuration. */
+               i = 0;
+               if (stp->dev_intlevel)
+                       i |= DDMA_CFG_SED;
+               if (stp->dev_intpolarity)
+                       i |= DDMA_CFG_SP;
+               if (dtp->dev_intlevel)
+                       i |= DDMA_CFG_DED;
+               if (dtp->dev_intpolarity)
+                       i |= DDMA_CFG_DP;
+               if ((stp->dev_flags & DEV_FLAGS_SYNC) ||
+                       (dtp->dev_flags & DEV_FLAGS_SYNC))
+                               i |= DDMA_CFG_SYNC;
+               cp->ddma_cfg = i;
+               au_sync();
+
+               /*
+                * Return a non-zero value that can be used to find the channel
+                * information in subsequent operations.
+                */
+               return (u32)(&chan_tab_ptr[chan]);
        }
-       return rv;
+
+       /* Release devices */
+       stp->dev_flags &= ~DEV_FLAGS_INUSE;
+       dtp->dev_flags &= ~DEV_FLAGS_INUSE;
+
+       return 0;
 }
 EXPORT_SYMBOL(au1xxx_dbdma_chan_alloc);