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path: root/drivers/dma/cppi41.c
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Diffstat (limited to 'drivers/dma/cppi41.c')
-rw-r--r--drivers/dma/cppi41.c69
1 files changed, 46 insertions, 23 deletions
diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c
index d5ba43a87a68..200828c60db9 100644
--- a/drivers/dma/cppi41.c
+++ b/drivers/dma/cppi41.c
@@ -153,6 +153,8 @@ struct cppi41_dd {
/* context for suspend/resume */
unsigned int dma_tdfdq;
+
+ bool is_suspended;
};
#define FIST_COMPLETION_QUEUE 93
@@ -257,6 +259,10 @@ static struct cppi41_channel *desc_to_chan(struct cppi41_dd *cdd, u32 desc)
BUG_ON(desc_num >= ALLOC_DECS_NUM);
c = cdd->chan_busy[desc_num];
cdd->chan_busy[desc_num] = NULL;
+
+ /* Usecount for chan_busy[], paired with push_desc_queue() */
+ pm_runtime_put(cdd->ddev.dev);
+
return c;
}
@@ -317,12 +323,12 @@ static irqreturn_t cppi41_irq(int irq, void *data)
while (val) {
u32 desc, len;
- int error;
- error = pm_runtime_get(cdd->ddev.dev);
- if (error < 0)
- dev_err(cdd->ddev.dev, "%s pm runtime get: %i\n",
- __func__, error);
+ /*
+ * This should never trigger, see the comments in
+ * push_desc_queue()
+ */
+ WARN_ON(cdd->is_suspended);
q_num = __fls(val);
val &= ~(1 << q_num);
@@ -343,9 +349,6 @@ static irqreturn_t cppi41_irq(int irq, void *data)
c->residue = pd_trans_len(c->desc->pd6) - len;
dma_cookie_complete(&c->txd);
dmaengine_desc_get_callback_invoke(&c->txd, NULL);
-
- pm_runtime_mark_last_busy(cdd->ddev.dev);
- pm_runtime_put_autosuspend(cdd->ddev.dev);
}
}
return IRQ_HANDLED;
@@ -447,6 +450,15 @@ static void push_desc_queue(struct cppi41_channel *c)
*/
__iowmb();
+ /*
+ * DMA transfers can take at least 200ms to complete with USB mass
+ * storage connected. To prevent autosuspend timeouts, we must use
+ * pm_runtime_get/put() when chan_busy[] is modified. This will get
+ * cleared in desc_to_chan() or cppi41_stop_chan() depending on the
+ * outcome of the transfer.
+ */
+ pm_runtime_get(cdd->ddev.dev);
+
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]);
@@ -457,20 +469,26 @@ static void push_desc_queue(struct cppi41_channel *c)
cppi_writel(reg, cdd->qmgr_mem + QMGR_QUEUE_D(c->q_num));
}
-static void pending_desc(struct cppi41_channel *c)
+/*
+ * Caller must hold cdd->lock to prevent push_desc_queue()
+ * getting called out of order. We have both cppi41_dma_issue_pending()
+ * and cppi41_runtime_resume() call this function.
+ */
+static void cppi41_run_queue(struct cppi41_dd *cdd)
{
- struct cppi41_dd *cdd = c->cdd;
- unsigned long flags;
+ struct cppi41_channel *c, *_c;
- spin_lock_irqsave(&cdd->lock, flags);
- list_add_tail(&c->node, &cdd->pending);
- spin_unlock_irqrestore(&cdd->lock, flags);
+ list_for_each_entry_safe(c, _c, &cdd->pending, node) {
+ push_desc_queue(c);
+ list_del(&c->node);
+ }
}
static void cppi41_dma_issue_pending(struct dma_chan *chan)
{
struct cppi41_channel *c = to_cpp41_chan(chan);
struct cppi41_dd *cdd = c->cdd;
+ unsigned long flags;
int error;
error = pm_runtime_get(cdd->ddev.dev);
@@ -482,10 +500,11 @@ static void cppi41_dma_issue_pending(struct dma_chan *chan)
return;
}
- if (likely(pm_runtime_active(cdd->ddev.dev)))
- push_desc_queue(c);
- else
- pending_desc(c);
+ spin_lock_irqsave(&cdd->lock, flags);
+ list_add_tail(&c->node, &cdd->pending);
+ if (!cdd->is_suspended)
+ cppi41_run_queue(cdd);
+ spin_unlock_irqrestore(&cdd->lock, flags);
pm_runtime_mark_last_busy(cdd->ddev.dev);
pm_runtime_put_autosuspend(cdd->ddev.dev);
@@ -705,6 +724,9 @@ static int cppi41_stop_chan(struct dma_chan *chan)
WARN_ON(!cdd->chan_busy[desc_num]);
cdd->chan_busy[desc_num] = NULL;
+ /* Usecount for chan_busy[], paired with push_desc_queue() */
+ pm_runtime_put(cdd->ddev.dev);
+
return 0;
}
@@ -1150,8 +1172,12 @@ static int __maybe_unused cppi41_resume(struct device *dev)
static int __maybe_unused cppi41_runtime_suspend(struct device *dev)
{
struct cppi41_dd *cdd = dev_get_drvdata(dev);
+ unsigned long flags;
+ spin_lock_irqsave(&cdd->lock, flags);
+ cdd->is_suspended = true;
WARN_ON(!list_empty(&cdd->pending));
+ spin_unlock_irqrestore(&cdd->lock, flags);
return 0;
}
@@ -1159,14 +1185,11 @@ static int __maybe_unused cppi41_runtime_suspend(struct device *dev)
static int __maybe_unused cppi41_runtime_resume(struct device *dev)
{
struct cppi41_dd *cdd = dev_get_drvdata(dev);
- struct cppi41_channel *c, *_c;
unsigned long flags;
spin_lock_irqsave(&cdd->lock, flags);
- list_for_each_entry_safe(c, _c, &cdd->pending, node) {
- push_desc_queue(c);
- list_del(&c->node);
- }
+ cdd->is_suspended = false;
+ cppi41_run_queue(cdd);
spin_unlock_irqrestore(&cdd->lock, flags);
return 0;