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>

1 files changed, 36 insertions, 23 deletions

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index ff9d6de2b746..83a8a1d125ac 100644
--- 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);
 }