usb: musb: musb_cppi41: Handle ISOCH differently and not use the hrtimer.

In case of ISOCH transfers the hrtimer workaround for the hardware issue
is not very reliable. Instead of checking musb_is_tx_fifo_empty() in hrtimer
routine, schedule a completion work and check the same in completion work.

Signed-off-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index 39ee516c8cbf..5b0f2a58f8ce 100644
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -39,6 +39,7 @@ struct cppi41_dma_channel {
         u32 transferred;
         u32 packet_sz;
         struct list_head tx_check;
+        struct work_struct dma_completion;
 };
 
 #define MUSB_DMA_NUM_CHANNELS 15
@@ -112,6 +113,18 @@ static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
         return true;
 }
 
+static bool is_isoc(struct musb_hw_ep *hw_ep, bool in)
+{
+        if (in && hw_ep->in_qh) {
+                if (hw_ep->in_qh->type == USB_ENDPOINT_XFER_ISOC)
+                        return true;
+        } else if (hw_ep->out_qh) {
+                if (hw_ep->out_qh->type == USB_ENDPOINT_XFER_ISOC)
+                        return true;
+        }
+        return false;
+}
+
 static void cppi41_dma_callback(void *private_data);
 
 static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
@@ -165,6 +178,32 @@ static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
         }
 }
 
+static void cppi_trans_done_work(struct work_struct *work)
+{
+        unsigned long flags;
+        struct cppi41_dma_channel *cppi41_channel =
+                container_of(work, struct cppi41_dma_channel, dma_completion);
+        struct cppi41_dma_controller *controller = cppi41_channel->controller;
+        struct musb *musb = controller->musb;
+        struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
+        bool empty;
+
+        if (!cppi41_channel->is_tx && is_isoc(hw_ep, 1)) {
+                spin_lock_irqsave(&musb->lock, flags);
+                cppi41_trans_done(cppi41_channel);
+                spin_unlock_irqrestore(&musb->lock, flags);
+        } else {
+                empty = musb_is_tx_fifo_empty(hw_ep);
+                if (empty) {
+                        spin_lock_irqsave(&musb->lock, flags);
+                        cppi41_trans_done(cppi41_channel);
+                        spin_unlock_irqrestore(&musb->lock, flags);
+                } else {
+                        schedule_work(&cppi41_channel->dma_completion);
+                }
+        }
+}
+
 static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
 {
         struct cppi41_dma_controller *controller;
@@ -228,6 +267,14 @@ static void cppi41_dma_callback(void *private_data)
                         transferred < cppi41_channel->packet_sz)
                 cppi41_channel->prog_len = 0;
 
+        if (!cppi41_channel->is_tx) {
+                if (is_isoc(hw_ep, 1))
+                        schedule_work(&cppi41_channel->dma_completion);
+                else
+                        cppi41_trans_done(cppi41_channel);
+                goto out;
+        }
+
         empty = musb_is_tx_fifo_empty(hw_ep);
         if (empty) {
                 cppi41_trans_done(cppi41_channel);
@@ -264,6 +311,10 @@ static void cppi41_dma_callback(void *private_data)
                                 goto out;
                         }
                 }
+                if (is_isoc(hw_ep, 0)) {
+                        schedule_work(&cppi41_channel->dma_completion);
+                        goto out;
+                }
                 list_add_tail(&cppi41_channel->tx_check,
                                 &controller->early_tx_list);
                 if (!hrtimer_active(&controller->early_tx)) {
@@ -620,6 +671,8 @@ static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
                 cppi41_channel->port_num = port;
                 cppi41_channel->is_tx = is_tx;
                 INIT_LIST_HEAD(&cppi41_channel->tx_check);
+                INIT_WORK(&cppi41_channel->dma_completion,
+                          cppi_trans_done_work);
 
                 musb_dma = &cppi41_channel->channel;
                 musb_dma->private_data = cppi41_channel;