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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-01 09:22:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-01 09:22:08 -0800
commit35609502ac5dea2b149ec0368791d9c0e246bd65 (patch)
tree6819f6bc5b8c3585b7a19cc0d8d25d703a1bc57c /drivers
parentc325b3533730016ca5cdaf902d62550b4243fe43 (diff)
parent91539eb1fda2d530d3b268eef542c5414e54bf1a (diff)
Merge tag 'dmaengine-fix-4.10-rc7' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine fixes from Vinod Koul: "A couple of fixes showed up late in the cycle so sending them up and sending early in the week and not on Friday :). They fix a double lock in pl330 driver and runtime pm fixes for cppi driver" * tag 'dmaengine-fix-4.10-rc7' of git://git.infradead.org/users/vkoul/slave-dma: dmaengine: pl330: fix double lock dmaengine: cppi41: Clean up pointless warnings dmaengine: cppi41: Fix oops in cppi41_runtime_resume dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage
Diffstat (limited to 'drivers')
-rw-r--r--drivers/dma/cppi41.c69
-rw-r--r--drivers/dma/pl330.c19
2 files changed, 52 insertions, 36 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;
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 740bbb942594..7539f73df9e0 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1699,7 +1699,6 @@ static bool _chan_ns(const struct pl330_dmac *pl330, int i)
static struct pl330_thread *pl330_request_channel(struct pl330_dmac *pl330)
{
struct pl330_thread *thrd = NULL;
- unsigned long flags;
int chans, i;
if (pl330->state == DYING)
@@ -1707,8 +1706,6 @@ static struct pl330_thread *pl330_request_channel(struct pl330_dmac *pl330)
chans = pl330->pcfg.num_chan;
- spin_lock_irqsave(&pl330->lock, flags);
-
for (i = 0; i < chans; i++) {
thrd = &pl330->channels[i];
if ((thrd->free) && (!_manager_ns(thrd) ||
@@ -1726,8 +1723,6 @@ static struct pl330_thread *pl330_request_channel(struct pl330_dmac *pl330)
thrd = NULL;
}
- spin_unlock_irqrestore(&pl330->lock, flags);
-
return thrd;
}
@@ -1745,7 +1740,6 @@ static inline void _free_event(struct pl330_thread *thrd, int ev)
static void pl330_release_channel(struct pl330_thread *thrd)
{
struct pl330_dmac *pl330;
- unsigned long flags;
if (!thrd || thrd->free)
return;
@@ -1757,10 +1751,8 @@ static void pl330_release_channel(struct pl330_thread *thrd)
pl330 = thrd->dmac;
- spin_lock_irqsave(&pl330->lock, flags);
_free_event(thrd, thrd->ev);
thrd->free = true;
- spin_unlock_irqrestore(&pl330->lock, flags);
}
/* Initialize the structure for PL330 configuration, that can be used
@@ -2122,20 +2114,20 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan)
struct pl330_dmac *pl330 = pch->dmac;
unsigned long flags;
- spin_lock_irqsave(&pch->lock, flags);
+ spin_lock_irqsave(&pl330->lock, flags);
dma_cookie_init(chan);
pch->cyclic = false;
pch->thread = pl330_request_channel(pl330);
if (!pch->thread) {
- spin_unlock_irqrestore(&pch->lock, flags);
+ spin_unlock_irqrestore(&pl330->lock, flags);
return -ENOMEM;
}
tasklet_init(&pch->task, pl330_tasklet, (unsigned long) pch);
- spin_unlock_irqrestore(&pch->lock, flags);
+ spin_unlock_irqrestore(&pl330->lock, flags);
return 1;
}
@@ -2238,12 +2230,13 @@ static int pl330_pause(struct dma_chan *chan)
static void pl330_free_chan_resources(struct dma_chan *chan)
{
struct dma_pl330_chan *pch = to_pchan(chan);
+ struct pl330_dmac *pl330 = pch->dmac;
unsigned long flags;
tasklet_kill(&pch->task);
pm_runtime_get_sync(pch->dmac->ddma.dev);
- spin_lock_irqsave(&pch->lock, flags);
+ spin_lock_irqsave(&pl330->lock, flags);
pl330_release_channel(pch->thread);
pch->thread = NULL;
@@ -2251,7 +2244,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan)
if (pch->cyclic)
list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool);
- spin_unlock_irqrestore(&pch->lock, flags);
+ spin_unlock_irqrestore(&pl330->lock, flags);
pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
pm_runtime_put_autosuspend(pch->dmac->ddma.dev);
}