Merge tag 'gpio-v3.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...

[karo-tx-linux.git] / drivers / dma / cppi41.c

diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c
index c18aebf7d5aa9a23199b556bc9b54c8b3237253d..8f8b0b608875642e6ee60877a805f61a33e7d8bb 100644 (file)
--- a/drivers/dma/cppi41.c
+++ b/drivers/dma/cppi41.c
@@ -86,6 +86,9 @@
 
 #define USBSS_IRQ_PD_COMP      (1 <<  2)
 
+/* Packet Descriptor */
+#define PD2_ZERO_LENGTH                (1 << 19)
+
 struct cppi41_channel {
        struct dma_chan chan;
        struct dma_async_tx_descriptor txd;
@@ -307,7 +310,7 @@ static irqreturn_t cppi41_irq(int irq, void *data)
                        __iormb();
 
                while (val) {
-                       u32 desc;
+                       u32 desc, len;
 
                        q_num = __fls(val);
                        val &= ~(1 << q_num);
@@ -319,9 +322,13 @@ static irqreturn_t cppi41_irq(int irq, void *data)
                                                q_num, desc);
                                continue;
                        }
-                       c->residue = pd_trans_len(c->desc->pd6) -
-                               pd_trans_len(c->desc->pd0);
 
+                       if (c->desc->pd2 & PD2_ZERO_LENGTH)
+                               len = 0;
+                       else
+                               len = pd_trans_len(c->desc->pd0);
+
+                       c->residue = pd_trans_len(c->desc->pd6) - len;
                        dma_cookie_complete(&c->txd);
                        c->txd.callback(c->txd.callback_param);
                }
@@ -620,12 +627,15 @@ static int cppi41_stop_chan(struct dma_chan *chan)
        u32 desc_phys;
        int ret;
 
+       desc_phys = lower_32_bits(c->desc_phys);
+       desc_num = (desc_phys - cdd->descs_phys) / sizeof(struct cppi41_desc);
+       if (!cdd->chan_busy[desc_num])
+               return 0;
+
        ret = cppi41_tear_down_chan(c);
        if (ret)
                return ret;
 
-       desc_phys = lower_32_bits(c->desc_phys);
-       desc_num = (desc_phys - cdd->descs_phys) / sizeof(struct cppi41_desc);
        WARN_ON(!cdd->chan_busy[desc_num]);
        cdd->chan_busy[desc_num] = NULL;