ETRAX-FS: Don't schedule DMA processing without active channels.

Avoid scheduling DMA processing when all channels are stopped or at
end-of-list.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5720 c046a42c-6fe2-441c-8c8c-71466251a162

diff --git a/hw/etraxfs_dma.c b/hw/etraxfs_dma.c
index a77339a..2e5de50 100644 (file)
--- a/hw/etraxfs_dma.c
+++ b/hw/etraxfs_dma.c
@@ -318,6 +318,8 @@ static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
                ctrl->channels[c].state = RUNNING;
        } else
                printf("WARNING: starting DMA ch %d with no client\n", c);
+
+        qemu_bh_schedule_idle(ctrl->bh);
 }
 
 static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
@@ -391,13 +393,16 @@ static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
                 qemu_irq_lower(ctrl->channels[c].irq[0]);
 }
 
-static void channel_out_run(struct fs_dma_ctrl *ctrl, int c)
+static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
 {
        uint32_t len;
        uint32_t saved_data_buf;
        unsigned char buf[2 * 1024];
 
-       while (ctrl->channels[c].eol != 1) {
+       if (ctrl->channels[c].eol)
+               return 0;
+
+       do {
                saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
 
                D(printf("ch=%d buf=%x after=%x saved_data_buf=%x\n",
@@ -466,7 +471,8 @@ static void channel_out_run(struct fs_dma_ctrl *ctrl, int c)
                        D(dump_d(c, &ctrl->channels[c].current_d));
                }
                ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
-       }
+       } while (!ctrl->channels[c].eol);
+       return 1;
 }
 
 static int channel_in_process(struct fs_dma_ctrl *ctrl, int c, 
@@ -539,11 +545,14 @@ static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
        return len;
 }
 
-static inline void channel_in_run(struct fs_dma_ctrl *ctrl, int c)
+static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
 {
-       if (ctrl->channels[c].client->client.pull)
+       if (ctrl->channels[c].client->client.pull) {
                ctrl->channels[c].client->client.pull(
                        ctrl->channels[c].client->client.opaque);
+               return 1;
+       } else
+               return 0;
 }
 
 static uint32_t dma_rinvalid (void *opaque, target_phys_addr_t addr)
@@ -673,7 +682,7 @@ static CPUWriteMemoryFunc *dma_write[] = {
        &dma_writel,
 };
 
-static void etraxfs_dmac_run(void *opaque)
+static int etraxfs_dmac_run(void *opaque)
 {
        struct fs_dma_ctrl *ctrl = opaque;
        int i;
@@ -685,13 +694,14 @@ static void etraxfs_dmac_run(void *opaque)
        {
                if (ctrl->channels[i].state == RUNNING)
                {
-                       p++;
-                       if (ctrl->channels[i].input)
-                               channel_in_run(ctrl, i);
-                       else
-                               channel_out_run(ctrl, i);
+                       if (ctrl->channels[i].input) {
+                               p += channel_in_run(ctrl, i);
+                       } else {
+                               p += channel_out_run(ctrl, i);
+                       }
                }
        }
+       return p;
 }
 
 int etraxfs_dmac_input(struct etraxfs_dma_client *client, 
@@ -722,9 +732,13 @@ void etraxfs_dmac_connect_client(void *opaque, int c,
 static void DMA_run(void *opaque)
 {
     struct fs_dma_ctrl *etraxfs_dmac = opaque;
+    int p = 1;
+
     if (vm_running)
-        etraxfs_dmac_run(etraxfs_dmac);
-    qemu_bh_schedule_idle(etraxfs_dmac->bh);
+        p = etraxfs_dmac_run(etraxfs_dmac);
+
+    if (p)
+        qemu_bh_schedule_idle(etraxfs_dmac->bh);
 }
 
 void *etraxfs_dmac_init(CPUState *env, 
@@ -738,7 +752,6 @@ void *etraxfs_dmac_init(CPUState *env,
                return NULL;
 
         ctrl->bh = qemu_bh_new(DMA_run, ctrl);
-        qemu_bh_schedule_idle(ctrl->bh);
 
        ctrl->base = base;
        ctrl->env = env;