DaVinci: EDMA: Fix Bug while obtaining contiguous params

The reserve_contiguous_params function is used to reserve
a set of contiguous PARAMs. If we do not find a complete
set of contiguous PARAMs, the functions still has to free
every PARAM that it found to be free in the process of finding a
complete set and thus marked as "in use".
This patch mainly deals with correctly handling the
freeing of PARAMs.

Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 24 insertions, 8 deletions

diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
index 8eda4c3be940..b097592a862e 100644
--- a/arch/arm/mach-davinci/dma.c
+++ b/arch/arm/mach-davinci/dma.c
@@ -515,17 +515,30 @@ static int reserve_contiguous_params(int ctlr, unsigned int id,
 {
         int i, j;
         unsigned int count = num_params;
+        int stop_param = start_param;
+        DECLARE_BITMAP(tmp_inuse, EDMA_MAX_PARAMENTRY);
 
         for (i = start_param; i < edma_info[ctlr]->num_slots; ++i) {
                 j = EDMA_CHAN_SLOT(i);
-                if (!test_and_set_bit(j, edma_info[ctlr]->edma_inuse))
+                if (!test_and_set_bit(j, edma_info[ctlr]->edma_inuse)) {
+                        /* Record our current beginning slot */
+                        if (count == num_params)
+                                stop_param = i;
+
                         count--;
+                        set_bit(j, tmp_inuse);
+
                         if (count == 0)
                                 break;
-                else if (id == EDMA_CONT_PARAMS_FIXED_EXACT)
-                        break;
-                else
-                        count = num_params;
+                } else {
+                        clear_bit(j, tmp_inuse);
+
+                        if (id == EDMA_CONT_PARAMS_FIXED_EXACT) {
+                                stop_param = i;
+                                break;
+                        } else
+                                count = num_params;
+                }
         }
 
         /*
@@ -534,12 +547,15 @@ static int reserve_contiguous_params(int ctlr, unsigned int id,
          * of contiguous parameter RAMs but do not find the exact number
          * requested as we may reach the total number of parameter RAMs
          */
-        if (count) {
-                for (j = i - num_params + count + 1; j <= i ; ++j)
+        if (i == edma_info[ctlr]->num_slots)
+                stop_param = i;
+
+        for (j = start_param; j < stop_param; j++)
+                if (test_bit(j, tmp_inuse))
                         clear_bit(j, edma_info[ctlr]->edma_inuse);
 
+        if (count)
                 return -EBUSY;
-        }
 
         for (j = i - num_params + 1; j <= i; ++j)
                 memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(j),