3 files changed, 39 insertions, 76 deletions

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 297f48b0cba9..07bca4970e50 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -79,6 +79,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #include <linux/dmapool.h>
 #include <linux/dmaengine.h>
 #include <linux/amba/bus.h>
@@ -235,16 +236,19 @@ static void pl08x_start_txd(struct pl08x_dma_chan *plchan,
 }
 
 /*
- * Overall DMAC remains enabled always.
+ * Pause the channel by setting the HALT bit.
  *
- * Disabling individual channels could lose data.
+ * For M->P transfers, pause the DMAC first and then stop the peripheral -
+ * the FIFO can only drain if the peripheral is still requesting data.
+ * (note: this can still timeout if the DMAC FIFO never drains of data.)
  *
- * Disable the peripheral DMA after disabling the DMAC in order to allow
- * the DMAC FIFO to drain, and hence allow the channel to show inactive
+ * For P->M transfers, disable the peripheral first to stop it filling
+ * the DMAC FIFO, and then pause the DMAC.
  */
 static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
 {
         u32 val;
+        int timeout;
 
         /* Set the HALT bit and wait for the FIFO to drain */
         val = readl(ch->base + PL080_CH_CONFIG);
@@ -252,8 +256,13 @@ static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
         writel(val, ch->base + PL080_CH_CONFIG);
 
         /* Wait for channel inactive */
-        while (pl08x_phy_channel_busy(ch))
-                cpu_relax();
+        for (timeout = 1000; timeout; timeout--) {
+                if (!pl08x_phy_channel_busy(ch))
+                        break;
+                udelay(1);
+        }
+        if (pl08x_phy_channel_busy(ch))
+                pr_err("pl08x: channel%u timeout waiting for pause\n", ch->id);
 }
 
 static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
@@ -267,19 +276,24 @@ static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
 }
 
 
-/* Stops the channel */
-static void pl08x_stop_phy_chan(struct pl08x_phy_chan *ch)
+/*
+ * pl08x_terminate_phy_chan() stops the channel, clears the FIFO and
+ * clears any pending interrupt status.  This should not be used for
+ * an on-going transfer, but as a method of shutting down a channel
+ * (eg, when it's no longer used) or terminating a transfer.
+ */
+static void pl08x_terminate_phy_chan(struct pl08x_driver_data *pl08x,
+        struct pl08x_phy_chan *ch)
 {
-        u32 val;
+        u32 val = readl(ch->base + PL080_CH_CONFIG);
 
-        pl08x_pause_phy_chan(ch);
+        val &= ~(PL080_CONFIG_ENABLE | PL080_CONFIG_ERR_IRQ_MASK |
+                 PL080_CONFIG_TC_IRQ_MASK);
 
-        /* Disable channel */
-        val = readl(ch->base + PL080_CH_CONFIG);
-        val &= ~PL080_CONFIG_ENABLE;
-        val &= ~PL080_CONFIG_ERR_IRQ_MASK;
-        val &= ~PL080_CONFIG_TC_IRQ_MASK;
         writel(val, ch->base + PL080_CH_CONFIG);
+
+        writel(1 << ch->id, pl08x->base + PL080_ERR_CLEAR);
+        writel(1 << ch->id, pl08x->base + PL080_TC_CLEAR);
 }
 
 static inline u32 get_bytes_in_cctl(u32 cctl)
@@ -404,13 +418,12 @@ static inline void pl08x_put_phy_channel(struct pl08x_driver_data *pl08x,
 {
         unsigned long flags;
 
+        spin_lock_irqsave(&ch->lock, flags);
+
         /* Stop the channel and clear its interrupts */
-        pl08x_stop_phy_chan(ch);
-        writel((1 << ch->id), pl08x->base + PL080_ERR_CLEAR);
-        writel((1 << ch->id), pl08x->base + PL080_TC_CLEAR);
+        pl08x_terminate_phy_chan(pl08x, ch);
 
         /* Mark it as free */
-        spin_lock_irqsave(&ch->lock, flags);
         ch->serving = NULL;
         spin_unlock_irqrestore(&ch->lock, flags);
 }
@@ -1449,7 +1462,7 @@ static int pl08x_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
                 plchan->state = PL08X_CHAN_IDLE;
 
                 if (plchan->phychan) {
-                        pl08x_stop_phy_chan(plchan->phychan);
+                        pl08x_terminate_phy_chan(pl08x, plchan->phychan);
 
                         /*
                          * Mark physical channel as free and free any slave
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 0123740b973d..b6d1455fa936 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -771,15 +771,15 @@ static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
         __raw_writel(1 << channel, sdma->regs + SDMA_H_START);
 }
 
-static dma_cookie_t sdma_assign_cookie(struct sdma_channel *sdma)
+static dma_cookie_t sdma_assign_cookie(struct sdma_channel *sdmac)
 {
-        dma_cookie_t cookie = sdma->chan.cookie;
+        dma_cookie_t cookie = sdmac->chan.cookie;
 
         if (++cookie < 0)
                 cookie = 1;
 
-        sdma->chan.cookie = cookie;
-        sdma->desc.cookie = cookie;
+        sdmac->chan.cookie = cookie;
+        sdmac->desc.cookie = cookie;
 
         return cookie;
 }
@@ -1142,7 +1142,7 @@ static int __init sdma_get_firmware(struct sdma_engine *sdma,
         /* download the RAM image for SDMA */
         sdma_load_script(sdma, ram_code,
                         header->ram_code_size,
-                        sdma->script_addrs->ram_code_start_addr);
+                        addr->ram_code_start_addr);
         clk_disable(sdma->clk);
 
         sdma_add_scripts(sdma, addr);
@@ -1354,7 +1354,7 @@ err_clk:
 err_request_region:
 err_irq:
         kfree(sdma);
-        return 0;
+        return ret;
 }
 
 static int __exit sdma_remove(struct platform_device *pdev)
diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c
index cb26ee9773d6..c1a125e7d1df 100644
--- a/drivers/dma/ipu/ipu_idmac.c
+++ b/drivers/dma/ipu/ipu_idmac.c
@@ -1145,29 +1145,6 @@ static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan,
         reg = idmac_read_icreg(ipu, IDMAC_CHA_EN);
         idmac_write_icreg(ipu, reg & ~chan_mask, IDMAC_CHA_EN);
 
-        /*
-         * Problem (observed with channel DMAIC_7): after enabling the channel
-         * and initialising buffers, there comes an interrupt with current still
-         * pointing at buffer 0, whereas it should use buffer 0 first and only
-         * generate an interrupt when it is done, then current should already
-         * point to buffer 1. This spurious interrupt also comes on channel
-         * DMASDC_0. With DMAIC_7 normally, is we just leave the ISR after the
-         * first interrupt, there comes the second with current correctly
-         * pointing to buffer 1 this time. But sometimes this second interrupt
-         * doesn't come and the channel hangs. Clearing BUFx_RDY when disabling
-         * the channel seems to prevent the channel from hanging, but it doesn't
-         * prevent the spurious interrupt. This might also be unsafe. Think
-         * about the IDMAC controller trying to switch to a buffer, when we
-         * clear the ready bit, and re-enable it a moment later.
-         */
-        reg = idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY);
-        idmac_write_ipureg(ipu, 0, IPU_CHA_BUF0_RDY);
-        idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF0_RDY);
-
-        reg = idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY);
-        idmac_write_ipureg(ipu, 0, IPU_CHA_BUF1_RDY);
-        idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF1_RDY);
-
         spin_unlock_irqrestore(&ipu->lock, flags);
 
         return 0;
@@ -1246,33 +1223,6 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
 
         /* Other interrupts do not interfere with this channel */
         spin_lock(&ichan->lock);
-        if (unlikely(chan_id != IDMAC_SDC_0 && chan_id != IDMAC_SDC_1 &&
-                     ((curbuf >> chan_id) & 1) == ichan->active_buffer &&
-                     !list_is_last(ichan->queue.next, &ichan->queue))) {
-                int i = 100;
-
-                /* This doesn't help. See comment in ipu_disable_channel() */
-                while (--i) {
-                        curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
-                        if (((curbuf >> chan_id) & 1) != ichan->active_buffer)
-                                break;
-                        cpu_relax();
-                }
-
-                if (!i) {
-                        spin_unlock(&ichan->lock);
-                        dev_dbg(dev,
-                                "IRQ on active buffer on channel %x, active "
-                                "%d, ready %x, %x, current %x!\n", chan_id,
-                                ichan->active_buffer, ready0, ready1, curbuf);
-                        return IRQ_NONE;
-                } else
-                        dev_dbg(dev,
-                                "Buffer deactivated on channel %x, active "
-                                "%d, ready %x, %x, current %x, rest %d!\n", chan_id,
-                                ichan->active_buffer, ready0, ready1, curbuf, i);
-        }
-
         if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) ||
                      (!ichan->active_buffer && (ready0 >> chan_id) & 1)
                      )) {