From 668d6d94a7085518fc84c3809b2ba6048eea431f Mon Sep 17 00:00:00 2001
From: Laxman Dewangan <ldewangan@nvidia.com>
Date: Wed, 21 Mar 2012 17:54:21 +0530
Subject: ARM: tegra: dma: Update actual bytes_transferred in dma cancel

When canceling dma, updating actual bytes transferred by dma,
making all requests status to aborted and deleting from channel
request queue.

Change-Id: I860780814340d54465de5b2ae11a6895319f428c
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/90815
Reviewed-by: Automatic_Commit_Validation_User
---
 arch/arm/mach-tegra/dma.c              | 84 ++++++++++++++++++++++++++++------
 arch/arm/mach-tegra/include/mach/dma.h |  9 ++++
 2 files changed, 78 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-tegra/dma.c b/arch/arm/mach-tegra/dma.c
index f8145844cb81..66f9c24a946c 100644
--- a/arch/arm/mach-tegra/dma.c
+++ b/arch/arm/mach-tegra/dma.c
@@ -157,6 +157,7 @@ static bool tegra_dma_update_hw_partial(struct tegra_dma_channel *ch,
 static void handle_oneshot_dma(struct tegra_dma_channel *ch);
 static void handle_continuous_dbl_dma(struct tegra_dma_channel *ch);
 static void handle_continuous_sngl_dma(struct tegra_dma_channel *ch);
+static void handle_dma_isr_locked(struct tegra_dma_channel *ch);
 
 void tegra_dma_flush(struct tegra_dma_channel *ch)
 {
@@ -180,21 +181,6 @@ static void tegra_dma_stop(struct tegra_dma_channel *ch)
 		writel(status, ch->addr + APB_DMA_CHAN_STA);
 }
 
-int tegra_dma_cancel(struct tegra_dma_channel *ch)
-{
-	unsigned long irq_flags;
-
-	spin_lock_irqsave(&ch->lock, irq_flags);
-	while (!list_empty(&ch->list))
-		list_del(ch->list.next);
-
-	tegra_dma_stop(ch);
-
-	spin_unlock_irqrestore(&ch->lock, irq_flags);
-	return 0;
-}
-EXPORT_SYMBOL(tegra_dma_cancel);
-
 static void pause_dma(bool wait_for_burst_complete)
 {
 	spin_lock(&enable_lock);
@@ -413,6 +399,74 @@ skip_status:
 }
 EXPORT_SYMBOL(tegra_dma_dequeue_req);
 
+int tegra_dma_cancel(struct tegra_dma_channel *ch)
+{
+	struct tegra_dma_req *hreq = NULL;
+	unsigned long status;
+	unsigned long irq_flags;
+	struct tegra_dma_req *cb_req = NULL;
+	dma_callback callback = NULL;
+	struct list_head new_list;
+
+	INIT_LIST_HEAD(&new_list);
+
+	if (ch->mode & TEGRA_DMA_SHARED) {
+		pr_err("Can not abort requests from shared channel %d\n",
+			ch->id);
+		return -EPERM;
+	}
+
+	spin_lock_irqsave(&ch->lock, irq_flags);
+
+	/* If list is empty, return with error*/
+	if (list_empty(&ch->list)) {
+		spin_unlock_irqrestore(&ch->lock, irq_flags);
+		return 0;
+	}
+
+	/* Pause dma before checking the queue status */
+	pause_dma(true);
+	status = readl(ch->addr + APB_DMA_CHAN_STA);
+	if (status & STA_ISE_EOC) {
+		handle_dma_isr_locked(ch);
+		cb_req = ch->cb_req;
+		callback = ch->callback;
+		ch->cb_req = NULL;
+		ch->callback = NULL;
+		/* Read status because it may get changed */
+		status = readl(ch->addr + APB_DMA_CHAN_STA);
+	}
+
+	/* Abort head requests, stop dma and dequeue all requests */
+	if (!list_empty(&ch->list)) {
+		tegra_dma_stop(ch);
+		hreq = list_entry(ch->list.next, typeof(*hreq), node);
+		hreq->bytes_transferred +=
+				get_current_xferred_count(ch, hreq, status);
+
+		/* copy the list into new list. */
+		list_replace_init(&ch->list, &new_list);
+	}
+
+	resume_dma();
+
+	spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+	/* Call callback if it is due from interrupts */
+	if (callback)
+		callback(cb_req);
+
+	/* Abort all requests on list. */
+	while (!list_empty(&new_list)) {
+		hreq = list_entry(new_list.next, typeof(*hreq), node);
+		hreq->status = -TEGRA_DMA_REQ_ERROR_ABORTED;
+		list_del(&hreq->node);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(tegra_dma_cancel);
+
 bool tegra_dma_is_empty(struct tegra_dma_channel *ch)
 {
 	unsigned long irq_flags;
diff --git a/arch/arm/mach-tegra/include/mach/dma.h b/arch/arm/mach-tegra/include/mach/dma.h
index 83840377b8b4..c6617e95c1af 100644
--- a/arch/arm/mach-tegra/include/mach/dma.h
+++ b/arch/arm/mach-tegra/include/mach/dma.h
@@ -189,6 +189,15 @@ bool tegra_dma_is_empty(struct tegra_dma_channel *ch);
 struct tegra_dma_channel *tegra_dma_allocate_channel(int mode,
 		const char namefmt[], ...);
 void tegra_dma_free_channel(struct tegra_dma_channel *ch);
+
+/*
+ * tegra_dma_cancel: Stop the dma and remove all request from pending request
+ * queue for transfer.
+ * The pending list for data transfer will become empty after this callback.
+ * The status of each request will be marked as ABORTED.
+ * bytes_transferred in each requests shows the actual bytes transferred by dma.
+ * Callbacks will not be called when cancel the requests.
+*/
 int tegra_dma_cancel(struct tegra_dma_channel *ch);
 
 int __init tegra_dma_init(void);
-- 
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