usb: musb: musb_cppi41: factor most of cppi41_dma_callback() into cppi41_trans_done()

This patch moves most of the logic in cppi41_dma_callback() into
cppi41_trans_done() where it can be called from another function.
Instead of computing "transferred" (the number of bytes transferred in
the last transaction) in cppi41_trans_done() the member
"cppi41_channel->prog_len" is now set to 0 if the transfer as a whole
can be considered as done. If it is != 0 then the next iteration is
assumed.
This is a preparation for a workaround.

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index ff9d6de..83a8a1d 100644 (file)
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -96,31 +96,15 @@ static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
        cppi41_channel->usb_toggle = toggle;
 }
 
-static void cppi41_dma_callback(void *private_data)
+static void cppi41_dma_callback(void *private_data);
+
+static void cppi41_trans_done(struct dma_channel *channel)
 {
-       struct dma_channel *channel = private_data;
        struct cppi41_dma_channel *cppi41_channel = channel->private_data;
        struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
        struct musb *musb = hw_ep->musb;
-       unsigned long flags;
-       struct dma_tx_state txstate;
-       u32 transferred;
 
-       spin_lock_irqsave(&musb->lock, flags);
-
-       dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
-                       &txstate);
-       transferred = cppi41_channel->prog_len - txstate.residue;
-       cppi41_channel->transferred += transferred;
-
-       dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
-               hw_ep->epnum, cppi41_channel->transferred,
-               cppi41_channel->total_len);
-
-       update_rx_toggle(cppi41_channel);
-
-       if (cppi41_channel->transferred == cppi41_channel->total_len ||
-                       transferred < cppi41_channel->packet_sz) {
+       if (!cppi41_channel->prog_len) {
 
                /* done, complete */
                cppi41_channel->channel.actual_len =
@@ -150,10 +134,8 @@ static void cppi41_dma_callback(void *private_data)
                                remain_bytes,
                                direction,
                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-               if (WARN_ON(!dma_desc)) {
-                       spin_unlock_irqrestore(&musb->lock, flags);
+               if (WARN_ON(!dma_desc))
                        return;
-               }
 
                dma_desc->callback = cppi41_dma_callback;
                dma_desc->callback_param = channel;
@@ -166,6 +148,37 @@ static void cppi41_dma_callback(void *private_data)
                        musb_writew(epio, MUSB_RXCSR, csr);
                }
        }
+}
+
+static void cppi41_dma_callback(void *private_data)
+{
+       struct dma_channel *channel = private_data;
+       struct cppi41_dma_channel *cppi41_channel = channel->private_data;
+       struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
+       struct musb *musb = hw_ep->musb;
+       unsigned long flags;
+       struct dma_tx_state txstate;
+       u32 transferred;
+
+       spin_lock_irqsave(&musb->lock, flags);
+
+       dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
+                       &txstate);
+       transferred = cppi41_channel->prog_len - txstate.residue;
+       cppi41_channel->transferred += transferred;
+
+       dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
+               hw_ep->epnum, cppi41_channel->transferred,
+               cppi41_channel->total_len);
+
+       update_rx_toggle(cppi41_channel);
+
+       if (cppi41_channel->transferred == cppi41_channel->total_len ||
+                       transferred < cppi41_channel->packet_sz)
+               cppi41_channel->prog_len = 0;
+
+       cppi41_trans_done(channel);
+
        spin_unlock_irqrestore(&musb->lock, flags);
 }