Merge tag 'dmaengine-fix-5.0-rc6' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:
 - Fix in at_xdmac fr wrongful channel state
 - Fix for imx driver for wrong callback invocation
 - Fix to bcm driver for interrupt race & transaction abort.
 - Fix in dmatest to abort in mapping error

* tag 'dmaengine-fix-5.0-rc6' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dmatest: Abort test in case of mapping error
  dmaengine: bcm2835: Fix abort of transactions
  dmaengine: bcm2835: Fix interrupt race on RT
  dmaengine: imx-dma: fix wrong callback invoke
  dmaengine: at_xdmac: Fix wrongfull report of a channel as in use

Author: torvalds

drivers/dma/at_xdmac.c

@@ -203,6 +203,7 @@ struct at_xdmac_chan {
 	u32				save_cim;
 	u32				save_cnda;
 	u32				save_cndc;
+	u32				irq_status;
 	unsigned long			status;
 	struct tasklet_struct		tasklet;
 	struct dma_slave_config		sconfig;
@@ -1580,24 +1581,24 @@ static void at_xdmac_tasklet(unsigned long data)
 	struct at_xdmac_desc	*desc;
 	u32			error_mask;
 
-	dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08lx\n",
-		 __func__, atchan->status);
+	dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08x\n",
+		__func__, atchan->irq_status);
 
 	error_mask = AT_XDMAC_CIS_RBEIS
 		     | AT_XDMAC_CIS_WBEIS
 		     | AT_XDMAC_CIS_ROIS;
 
 	if (at_xdmac_chan_is_cyclic(atchan)) {
 		at_xdmac_handle_cyclic(atchan);
-	} else if ((atchan->status & AT_XDMAC_CIS_LIS)
-		   || (atchan->status & error_mask)) {
+	} else if ((atchan->irq_status & AT_XDMAC_CIS_LIS)
+		   || (atchan->irq_status & error_mask)) {
 		struct dma_async_tx_descriptor  *txd;
 
-		if (atchan->status & AT_XDMAC_CIS_RBEIS)
+		if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
 			dev_err(chan2dev(&atchan->chan), "read bus error!!!");
-		if (atchan->status & AT_XDMAC_CIS_WBEIS)
+		if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
 			dev_err(chan2dev(&atchan->chan), "write bus error!!!");
-		if (atchan->status & AT_XDMAC_CIS_ROIS)
+		if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
 			dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
 
 		spin_lock(&atchan->lock);
@@ -1652,7 +1653,7 @@ static irqreturn_t at_xdmac_interrupt(int irq, void *dev_id)
 			atchan = &atxdmac->chan[i];
 			chan_imr = at_xdmac_chan_read(atchan, AT_XDMAC_CIM);
 			chan_status = at_xdmac_chan_read(atchan, AT_XDMAC_CIS);
-			atchan->status = chan_status & chan_imr;
+			atchan->irq_status = chan_status & chan_imr;
 			dev_vdbg(atxdmac->dma.dev,
 				 "%s: chan%d: imr=0x%x, status=0x%x\n",
 				 __func__, i, chan_imr, chan_status);
@@ -1666,7 +1667,7 @@ static irqreturn_t at_xdmac_interrupt(int irq, void *dev_id)
 				 at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
 				 at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
 
-			if (atchan->status & (AT_XDMAC_CIS_RBEIS | AT_XDMAC_CIS_WBEIS))
+			if (atchan->irq_status & (AT_XDMAC_CIS_RBEIS | AT_XDMAC_CIS_WBEIS))
 				at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
 
 			tasklet_schedule(&atchan->tasklet);

drivers/dma/bcm2835-dma.c

@@ -406,38 +406,32 @@ static void bcm2835_dma_fill_cb_chain_with_sg(
 	}
 }
 
-static int bcm2835_dma_abort(void __iomem *chan_base)
+static int bcm2835_dma_abort(struct bcm2835_chan *c)
 {
-	unsigned long cs;
+	void __iomem *chan_base = c->chan_base;
 	long int timeout = 10000;
 
-	cs = readl(chan_base + BCM2835_DMA_CS);
-	if (!(cs & BCM2835_DMA_ACTIVE))
+	/*
+	 * A zero control block address means the channel is idle.
+	 * (The ACTIVE flag in the CS register is not a reliable indicator.)
+	 */
+	if (!readl(chan_base + BCM2835_DMA_ADDR))
 		return 0;
 
 	/* Write 0 to the active bit - Pause the DMA */
 	writel(0, chan_base + BCM2835_DMA_CS);
 
 	/* Wait for any current AXI transfer to complete */
-	while ((cs & BCM2835_DMA_ISPAUSED) && --timeout) {
+	while ((readl(chan_base + BCM2835_DMA_CS) &
+		BCM2835_DMA_WAITING_FOR_WRITES) && --timeout)
 		cpu_relax();
-		cs = readl(chan_base + BCM2835_DMA_CS);
-	}
 
-	/* We'll un-pause when we set of our next DMA */
+	/* Peripheral might be stuck and fail to signal AXI write responses */
 	if (!timeout)
-		return -ETIMEDOUT;
-
-	if (!(cs & BCM2835_DMA_ACTIVE))
-		return 0;
-
-	/* Terminate the control block chain */
-	writel(0, chan_base + BCM2835_DMA_NEXTCB);
-
-	/* Abort the whole DMA */
-	writel(BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE,
-	       chan_base + BCM2835_DMA_CS);
+		dev_err(c->vc.chan.device->dev,
+			"failed to complete outstanding writes\n");
 
+	writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
 	return 0;
 }
 
@@ -476,20 +470,23 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data)
 
 	spin_lock_irqsave(&c->vc.lock, flags);
 
-	/* Acknowledge interrupt */
-	writel(BCM2835_DMA_INT, c->chan_base + BCM2835_DMA_CS);
+	/*
+	 * Clear the INT flag to receive further interrupts. Keep the channel
+	 * active in case the descriptor is cyclic or in case the client has
+	 * already terminated the descriptor and issued a new one. (May happen
+	 * if this IRQ handler is threaded.) If the channel is finished, it
+	 * will remain idle despite the ACTIVE flag being set.
+	 */
+	writel(BCM2835_DMA_INT | BCM2835_DMA_ACTIVE,
+	       c->chan_base + BCM2835_DMA_CS);
 
 	d = c->desc;
 
 	if (d) {
 		if (d->cyclic) {
 			/* call the cyclic callback */
 			vchan_cyclic_callback(&d->vd);
-
-			/* Keep the DMA engine running */
-			writel(BCM2835_DMA_ACTIVE,
-			       c->chan_base + BCM2835_DMA_CS);
-		} else {
+		} else if (!readl(c->chan_base + BCM2835_DMA_ADDR)) {
 			vchan_cookie_complete(&c->desc->vd);
 			bcm2835_dma_start_desc(c);
 		}
@@ -779,7 +776,6 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan)
 	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
 	struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
 	unsigned long flags;
-	int timeout = 10000;
 	LIST_HEAD(head);
 
 	spin_lock_irqsave(&c->vc.lock, flags);
@@ -789,27 +785,11 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan)
 	list_del_init(&c->node);
 	spin_unlock(&d->lock);
 
-	/*
-	 * Stop DMA activity: we assume the callback will not be called
-	 * after bcm_dma_abort() returns (even if it does, it will see
-	 * c->desc is NULL and exit.)
-	 */
+	/* stop DMA activity */
 	if (c->desc) {
 		vchan_terminate_vdesc(&c->desc->vd);
 		c->desc = NULL;
-		bcm2835_dma_abort(c->chan_base);
-
-		/* Wait for stopping */
-		while (--timeout) {
-			if (!(readl(c->chan_base + BCM2835_DMA_CS) &
-						BCM2835_DMA_ACTIVE))
-				break;
-
-			cpu_relax();
-		}
-
-		if (!timeout)
-			dev_err(d->ddev.dev, "DMA transfer could not be terminated\n");
+		bcm2835_dma_abort(c);
 	}
 
 	vchan_get_all_descriptors(&c->vc, &head);

drivers/dma/dmatest.c

@@ -711,11 +711,9 @@ static int dmatest_func(void *data)
 			srcs[i] = um->addr[i] + src_off;
 			ret = dma_mapping_error(dev->dev, um->addr[i]);
 			if (ret) {
-				dmaengine_unmap_put(um);
 				result("src mapping error", total_tests,
 				       src_off, dst_off, len, ret);
-				failed_tests++;
-				continue;
+				goto error_unmap_continue;
 			}
 			um->to_cnt++;
 		}
@@ -730,11 +728,9 @@ static int dmatest_func(void *data)
 					       DMA_BIDIRECTIONAL);
 			ret = dma_mapping_error(dev->dev, dsts[i]);
 			if (ret) {
-				dmaengine_unmap_put(um);
 				result("dst mapping error", total_tests,
 				       src_off, dst_off, len, ret);
-				failed_tests++;
-				continue;
+				goto error_unmap_continue;
 			}
 			um->bidi_cnt++;
 		}
@@ -762,12 +758,10 @@ static int dmatest_func(void *data)
 		}
 
 		if (!tx) {
-			dmaengine_unmap_put(um);
 			result("prep error", total_tests, src_off,
 			       dst_off, len, ret);
 			msleep(100);
-			failed_tests++;
-			continue;
+			goto error_unmap_continue;
 		}
 
 		done->done = false;
@@ -776,12 +770,10 @@ static int dmatest_func(void *data)
 		cookie = tx->tx_submit(tx);
 
 		if (dma_submit_error(cookie)) {
-			dmaengine_unmap_put(um);
 			result("submit error", total_tests, src_off,
 			       dst_off, len, ret);
 			msleep(100);
-			failed_tests++;
-			continue;
+			goto error_unmap_continue;
 		}
 		dma_async_issue_pending(chan);
 
@@ -790,22 +782,20 @@ static int dmatest_func(void *data)
 
 		status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
 
-		dmaengine_unmap_put(um);
-
 		if (!done->done) {
 			result("test timed out", total_tests, src_off, dst_off,
 			       len, 0);
-			failed_tests++;
-			continue;
+			goto error_unmap_continue;
 		} else if (status != DMA_COMPLETE) {
 			result(status == DMA_ERROR ?
 			       "completion error status" :
 			       "completion busy status", total_tests, src_off,
 			       dst_off, len, ret);
-			failed_tests++;
-			continue;
+			goto error_unmap_continue;
 		}
 
+		dmaengine_unmap_put(um);
+
 		if (params->noverify) {
 			verbose_result("test passed", total_tests, src_off,
 				       dst_off, len, 0);
@@ -846,6 +836,12 @@ static int dmatest_func(void *data)
 			verbose_result("test passed", total_tests, src_off,
 				       dst_off, len, 0);
 		}
+
+		continue;
+
+error_unmap_continue:
+		dmaengine_unmap_put(um);
+		failed_tests++;
 	}
 	ktime = ktime_sub(ktime_get(), ktime);
 	ktime = ktime_sub(ktime, comparetime);

drivers/dma/imx-dma.c

@@ -618,7 +618,7 @@ static void imxdma_tasklet(unsigned long data)
 {
 	struct imxdma_channel *imxdmac = (void *)data;
 	struct imxdma_engine *imxdma = imxdmac->imxdma;
-	struct imxdma_desc *desc;
+	struct imxdma_desc *desc, *next_desc;
 	unsigned long flags;
 
 	spin_lock_irqsave(&imxdma->lock, flags);
@@ -648,10 +648,10 @@ static void imxdma_tasklet(unsigned long data)
 	list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free);
 
 	if (!list_empty(&imxdmac->ld_queue)) {
-		desc = list_first_entry(&imxdmac->ld_queue, struct imxdma_desc,
-					node);
+		next_desc = list_first_entry(&imxdmac->ld_queue,
+					     struct imxdma_desc, node);
 		list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active);
-		if (imxdma_xfer_desc(desc) < 0)
+		if (imxdma_xfer_desc(next_desc) < 0)
 			dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n",
 				 __func__, imxdmac->channel);
 	}