ARM: PL08x: remove circular buffer support

The driver already won't initialize a channel with a circular buffer;
the check in pl08x_prep_channel_resources() sees to that.  Remove
circular buffer support for the time being.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 20 insertions, 51 deletions

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index b721ed2e884d..74b35910f295 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -927,39 +927,21 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                         __func__, (u32) MAX_NUM_TSFR_LLIS);
                 return 0;
         }
+
+        llis_va = txd->llis_va;
         /*
-         * Decide whether this is a loop or a terminated transfer
+         * The final LLI terminates the LLI.
          */
-        llis_va = txd->llis_va;
-        llis_bus = (struct lli *) txd->llis_bus;
-
-        if (cd->circular_buffer) {
-                /*
-                 * Loop the circular buffer so that the next element
-                 * points back to the beginning of the LLI.
-                 */
-                llis_va[num_llis - 1].next =
-                        (dma_addr_t)((unsigned int)&(llis_bus[0]));
-        } else {
-                /*
-                 * On non-circular buffers, the final LLI terminates
-                 * the LLI.
-                 */
-                llis_va[num_llis - 1].next = 0;
-                /*
-                 * The final LLI element shall also fire an interrupt
-                 */
-                llis_va[num_llis - 1].cctl |= PL080_CONTROL_TC_IRQ_EN;
-        }
+        llis_va[num_llis - 1].next = 0;
+        /*
+         * The final LLI element shall also fire an interrupt
+         */
+        llis_va[num_llis - 1].cctl |= PL080_CONTROL_TC_IRQ_EN;
 
         /* Now store the channel register values */
         txd->csrc = llis_va[0].src;
         txd->cdst = llis_va[0].dst;
-        if (num_llis > 1)
-                txd->clli = llis_va[0].next;
-        else
-                txd->clli = 0;
-
+        txd->clli = llis_va[0].next;
         txd->cctl = llis_va[0].cctl;
         /* ccfg will be set at physical channel allocation time */
 
@@ -1334,19 +1316,7 @@ static int pl08x_prep_channel_resources(struct pl08x_dma_chan *plchan,
 
         spin_lock_irqsave(&plchan->lock, plchan->lockflags);
 
-        /*
-         * If this device is not using a circular buffer then
-         * queue this new descriptor for transfer.
-         * The descriptor for a circular buffer continues
-         * to be used until the channel is freed.
-         */
-        if (txd->cd->circular_buffer)
-                dev_err(&pl08x->adev->dev,
-                        "%s attempting to queue a circular buffer\n",
-                        __func__);
-        else
-                list_add_tail(&txd->node,
-                              &plchan->desc_list);
+        list_add_tail(&txd->node, &plchan->desc_list);
 
         /*
          * See if we already have a physical channel allocated,
@@ -1643,18 +1613,10 @@ static void pl08x_tasklet(unsigned long data)
                         callback(callback_param);
 
                 /*
-                 * Free the descriptor if it's not for a device
-                 * using a circular buffer
-                 */
-                if (!plchan->at->cd->circular_buffer) {
-                        pl08x_free_txd(pl08x, plchan->at);
-                        plchan->at = NULL;
-                }
-                /*
-                 * else descriptor for circular
-                 * buffers only freed when
-                 * client has disabled dma
+                 * Free the descriptor
                  */
+                pl08x_free_txd(pl08x, plchan->at);
+                plchan->at = NULL;
         }
         /*
          * If a new descriptor is queued, set it up
@@ -1799,6 +1761,13 @@ static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
                                 return -ENOMEM;
                         }
                 }
+                if (chan->cd->circular_buffer) {
+                        dev_err(&pl08x->adev->dev,
+                                "channel %s: circular buffers not supported\n",
+                                chan->name);
+                        kfree(chan);
+                        continue;
+                }
                 dev_info(&pl08x->adev->dev,
                          "initialize virtual channel \"%s\"\n",
                          chan->name);