Title: [6903] trunk/arch/blackfin/kernel/bfin_dma_5xx.c: early_dma_memcpy: tweak config checking pointed out by Yi, and simplify/fix config resetting once we do have an available channel that was previously used
- Revision
- 6903
- Author
- vapier
- Date
- 2009-07-01 13:48:03 -0500 (Wed, 01 Jul 2009)
Log Message
early_dma_memcpy: tweak config checking pointed out by Yi, and simplify/fix config resetting once we do have an available channel that was previously used
Modified Paths
Diff
Modified: trunk/arch/blackfin/kernel/bfin_dma_5xx.c (6902 => 6903)
--- trunk/arch/blackfin/kernel/bfin_dma_5xx.c 2009-07-01 16:11:38 UTC (rev 6902)
+++ trunk/arch/blackfin/kernel/bfin_dma_5xx.c 2009-07-01 18:48:03 UTC (rev 6903)
@@ -253,32 +253,31 @@
BUG_ON(src % 4);
BUG_ON(size % 4);
- /* Force a sync in case a previous config reset on this channel
- * occurred. This is needed so subsequent writes to DMA registers
- * are not spuriously lost/corrupted.
- */
- __builtin_bfin_ssync();
-
src_ch = 0;
/* Find an avalible memDMA channel */
while (1) {
- if (!src_ch || src_ch == (struct dma_register *)MDMA_S1_NEXT_DESC_PTR) {
- dst_ch = (struct dma_register *)MDMA_D0_NEXT_DESC_PTR;
- src_ch = (struct dma_register *)MDMA_S0_NEXT_DESC_PTR;
- } else {
+ if (src_ch == (struct dma_register *)MDMA_S0_NEXT_DESC_PTR) {
dst_ch = (struct dma_register *)MDMA_D1_NEXT_DESC_PTR;
src_ch = (struct dma_register *)MDMA_S1_NEXT_DESC_PTR;
+ } else {
+ dst_ch = (struct dma_register *)MDMA_D0_NEXT_DESC_PTR;
+ src_ch = (struct dma_register *)MDMA_S0_NEXT_DESC_PTR;
}
- if (!bfin_read16(&dst_ch->cfg)) {
+ if (!bfin_read16(&src_ch->cfg))
break;
- } else {
- if (bfin_read16(&dst_ch->irq_status) & DMA_DONE)
- bfin_write16(&dst_ch->cfg, 0);
+ else if (bfin_read16(&dst_ch->irq_status) & DMA_DONE) {
+ bfin_write16(&src_ch->cfg, 0);
+ break;
}
-
}
+ /* Force a sync in case a previous config reset on this channel
+ * occurred. This is needed so subsequent writes to DMA registers
+ * are not spuriously lost/corrupted.
+ */
+ __builtin_bfin_ssync();
+
/* Destination */
bfin_write32(&dst_ch->start_addr, dst);
bfin_write16(&dst_ch->x_count, size >> 2);
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