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>

diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
index 8eda4c3..b097592 100644 (file)
--- 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),