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dmaengine/dw_dmac: Replace spin_lock* with irqsave variants and enable submission from callback

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dmaengine routines can be called from interrupt context and with interrupts
disabled.  Whereas spin_unlock_bh can't be called from such contexts. So this
patch converts all spin_*_bh routines to irqsave variants.

Also, spin_lock() used in tasklet is converted to irqsave variants, as tasklet
can be interrupted, and dma requests from such interruptions may also call
spin_lock.

Now, submission from callbacks are permitted as per dmaengine framework. So we
shouldn't hold any locks while calling callbacks. As locks were taken by parent
routines, so releasing them before calling callbacks doesn't look clean enough.
So, locks are taken inside all routine now, whereever they are required. And
dwc_descriptor_complete is always called without taking locks.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Viresh Kumar 2011-04-15 16:03:35 +05:30 committed by Vinod Koul
parent 69dc14b51c
commit 69cea5a00d
1 changed files with 77 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

116
drivers/dma/dw_dmac.c
View File

@ -93,8 +93,9 @@ static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
struct dw_desc *desc, *_desc; struct dw_desc *desc, *_desc;
struct dw_desc *ret = NULL; struct dw_desc *ret = NULL;
unsigned int i = 0; unsigned int i = 0;
unsigned long flags;
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) { list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
if (async_tx_test_ack(&desc->txd)) { if (async_tx_test_ack(&desc->txd)) {
list_del(&desc->desc_node); list_del(&desc->desc_node);
@ -104,7 +105,7 @@ static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc); dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
i++; i++;
} }
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i); dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
@ -130,12 +131,14 @@ static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
*/ */
static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc) static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
{ {
unsigned long flags;
if (desc) { if (desc) {
struct dw_desc *child; struct dw_desc *child;
dwc_sync_desc_for_cpu(dwc, desc); dwc_sync_desc_for_cpu(dwc, desc);
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
list_for_each_entry(child, &desc->tx_list, desc_node) list_for_each_entry(child, &desc->tx_list, desc_node)
dev_vdbg(chan2dev(&dwc->chan), dev_vdbg(chan2dev(&dwc->chan),
"moving child desc %p to freelist\n", "moving child desc %p to freelist\n",
@ -143,7 +146,7 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
list_splice_init(&desc->tx_list, &dwc->free_list); list_splice_init(&desc->tx_list, &dwc->free_list);
dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc); dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
list_add(&desc->desc_node, &dwc->free_list); list_add(&desc->desc_node, &dwc->free_list);
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
} }
} }
@ -202,9 +205,11 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
void *param = NULL; void *param = NULL;
struct dma_async_tx_descriptor *txd = &desc->txd; struct dma_async_tx_descriptor *txd = &desc->txd;
struct dw_desc *child; struct dw_desc *child;
unsigned long flags;
dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie); dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
spin_lock_irqsave(&dwc->lock, flags);
dwc->completed = txd->cookie; dwc->completed = txd->cookie;
if (callback_required) { if (callback_required) {
callback = txd->callback; callback = txd->callback;
@ -241,6 +246,8 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
} }
} }
spin_unlock_irqrestore(&dwc->lock, flags);
if (callback_required && callback) if (callback_required && callback)
callback(param); callback(param);
} }
@ -249,7 +256,9 @@ static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
{ {
struct dw_desc *desc, *_desc; struct dw_desc *desc, *_desc;
LIST_HEAD(list); LIST_HEAD(list);
unsigned long flags;
spin_lock_irqsave(&dwc->lock, flags);
if (dma_readl(dw, CH_EN) & dwc->mask) { if (dma_readl(dw, CH_EN) & dwc->mask) {
dev_err(chan2dev(&dwc->chan), dev_err(chan2dev(&dwc->chan),
"BUG: XFER bit set, but channel not idle!\n"); "BUG: XFER bit set, but channel not idle!\n");
@ -270,6 +279,8 @@ static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
dwc_dostart(dwc, dwc_first_active(dwc)); dwc_dostart(dwc, dwc_first_active(dwc));
} }
spin_unlock_irqrestore(&dwc->lock, flags);
list_for_each_entry_safe(desc, _desc, &list, desc_node) list_for_each_entry_safe(desc, _desc, &list, desc_node)
dwc_descriptor_complete(dwc, desc, true); dwc_descriptor_complete(dwc, desc, true);
} }
@ -280,7 +291,9 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
struct dw_desc *desc, *_desc; struct dw_desc *desc, *_desc;
struct dw_desc *child; struct dw_desc *child;
u32 status_xfer; u32 status_xfer;
unsigned long flags;
spin_lock_irqsave(&dwc->lock, flags);
/* /*
* Clear block interrupt flag before scanning so that we don't * Clear block interrupt flag before scanning so that we don't
* miss any, and read LLP before RAW_XFER to ensure it is * miss any, and read LLP before RAW_XFER to ensure it is
@ -293,35 +306,47 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
if (status_xfer & dwc->mask) { if (status_xfer & dwc->mask) {
/* Everything we've submitted is done */ /* Everything we've submitted is done */
dma_writel(dw, CLEAR.XFER, dwc->mask); dma_writel(dw, CLEAR.XFER, dwc->mask);
spin_unlock_irqrestore(&dwc->lock, flags);
dwc_complete_all(dw, dwc); dwc_complete_all(dw, dwc);
return; return;
} }
if (list_empty(&dwc->active_list)) if (list_empty(&dwc->active_list)) {
spin_unlock_irqrestore(&dwc->lock, flags);
return; return;
}
dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp); dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) { list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
/* check first descriptors addr */ /* check first descriptors addr */
if (desc->txd.phys == llp) if (desc->txd.phys == llp) {
spin_unlock_irqrestore(&dwc->lock, flags);
return; return;
}
/* check first descriptors llp */ /* check first descriptors llp */
if (desc->lli.llp == llp) if (desc->lli.llp == llp) {
/* This one is currently in progress */ /* This one is currently in progress */
spin_unlock_irqrestore(&dwc->lock, flags);
return; return;
}
list_for_each_entry(child, &desc->tx_list, desc_node) list_for_each_entry(child, &desc->tx_list, desc_node)
if (child->lli.llp == llp) if (child->lli.llp == llp) {
/* Currently in progress */ /* Currently in progress */
spin_unlock_irqrestore(&dwc->lock, flags);
return; return;
}
/* /*
* No descriptors so far seem to be in progress, i.e. * No descriptors so far seem to be in progress, i.e.
* this one must be done. * this one must be done.
*/ */
spin_unlock_irqrestore(&dwc->lock, flags);
dwc_descriptor_complete(dwc, desc, true); dwc_descriptor_complete(dwc, desc, true);
spin_lock_irqsave(&dwc->lock, flags);
} }
dev_err(chan2dev(&dwc->chan), dev_err(chan2dev(&dwc->chan),
@ -336,6 +361,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
list_move(dwc->queue.next, &dwc->active_list); list_move(dwc->queue.next, &dwc->active_list);
dwc_dostart(dwc, dwc_first_active(dwc)); dwc_dostart(dwc, dwc_first_active(dwc));
} }
spin_unlock_irqrestore(&dwc->lock, flags);
} }
static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli) static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
@ -350,9 +376,12 @@ static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
{ {
struct dw_desc *bad_desc; struct dw_desc *bad_desc;
struct dw_desc *child; struct dw_desc *child;
unsigned long flags;
dwc_scan_descriptors(dw, dwc); dwc_scan_descriptors(dw, dwc);
spin_lock_irqsave(&dwc->lock, flags);
/* /*
* The descriptor currently at the head of the active list is * The descriptor currently at the head of the active list is
* borked. Since we don't have any way to report errors, we'll * borked. Since we don't have any way to report errors, we'll
@ -382,6 +411,8 @@ static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
list_for_each_entry(child, &bad_desc->tx_list, desc_node) list_for_each_entry(child, &bad_desc->tx_list, desc_node)
dwc_dump_lli(dwc, &child->lli); dwc_dump_lli(dwc, &child->lli);
spin_unlock_irqrestore(&dwc->lock, flags);
/* Pretend the descriptor completed successfully */ /* Pretend the descriptor completed successfully */
dwc_descriptor_complete(dwc, bad_desc, true); dwc_descriptor_complete(dwc, bad_desc, true);
} }
@ -406,6 +437,8 @@ EXPORT_SYMBOL(dw_dma_get_dst_addr);
static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc, static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
u32 status_block, u32 status_err, u32 status_xfer) u32 status_block, u32 status_err, u32 status_xfer)
{ {
unsigned long flags;
if (status_block & dwc->mask) { if (status_block & dwc->mask) {
void (*callback)(void *param); void (*callback)(void *param);
void *callback_param; void *callback_param;
@ -416,11 +449,9 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
callback = dwc->cdesc->period_callback; callback = dwc->cdesc->period_callback;
callback_param = dwc->cdesc->period_callback_param; callback_param = dwc->cdesc->period_callback_param;
if (callback) {
spin_unlock(&dwc->lock); if (callback)
callback(callback_param); callback(callback_param);
spin_lock(&dwc->lock);
}
} }
/* /*
@ -434,6 +465,9 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s " dev_err(chan2dev(&dwc->chan), "cyclic DMA unexpected %s "
"interrupt, stopping DMA transfer\n", "interrupt, stopping DMA transfer\n",
status_xfer ? "xfer" : "error"); status_xfer ? "xfer" : "error");
spin_lock_irqsave(&dwc->lock, flags);
dev_err(chan2dev(&dwc->chan), dev_err(chan2dev(&dwc->chan),
" SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n", " SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
channel_readl(dwc, SAR), channel_readl(dwc, SAR),
@ -457,6 +491,8 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
for (i = 0; i < dwc->cdesc->periods; i++) for (i = 0; i < dwc->cdesc->periods; i++)
dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli); dwc_dump_lli(dwc, &dwc->cdesc->desc[i]->lli);
spin_unlock_irqrestore(&dwc->lock, flags);
} }
} }
@ -480,7 +516,6 @@ static void dw_dma_tasklet(unsigned long data)
for (i = 0; i < dw->dma.chancnt; i++) { for (i = 0; i < dw->dma.chancnt; i++) {
dwc = &dw->chan[i]; dwc = &dw->chan[i];
spin_lock(&dwc->lock);
if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
dwc_handle_cyclic(dw, dwc, status_block, status_err, dwc_handle_cyclic(dw, dwc, status_block, status_err,
status_xfer); status_xfer);
@ -488,7 +523,6 @@ static void dw_dma_tasklet(unsigned long data)
dwc_handle_error(dw, dwc); dwc_handle_error(dw, dwc);
else if ((status_block | status_xfer) & (1 << i)) else if ((status_block | status_xfer) & (1 << i))
dwc_scan_descriptors(dw, dwc); dwc_scan_descriptors(dw, dwc);
spin_unlock(&dwc->lock);
} }
/* /*
@ -543,8 +577,9 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
struct dw_desc *desc = txd_to_dw_desc(tx); struct dw_desc *desc = txd_to_dw_desc(tx);
struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan); struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
dma_cookie_t cookie; dma_cookie_t cookie;
unsigned long flags;
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
cookie = dwc_assign_cookie(dwc, desc); cookie = dwc_assign_cookie(dwc, desc);
/* /*
@ -564,7 +599,7 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
list_add_tail(&desc->desc_node, &dwc->queue); list_add_tail(&desc->desc_node, &dwc->queue);
} }
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
return cookie; return cookie;
} }
@ -826,6 +861,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(chan->device); struct dw_dma *dw = to_dw_dma(chan->device);
struct dw_desc *desc, *_desc; struct dw_desc *desc, *_desc;
unsigned long flags;
LIST_HEAD(list); LIST_HEAD(list);
/* Only supports DMA_TERMINATE_ALL */ /* Only supports DMA_TERMINATE_ALL */
@ -838,7 +874,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
* channel. We still have to poll the channel enable bit due * channel. We still have to poll the channel enable bit due
* to AHB/HSB limitations. * to AHB/HSB limitations.
*/ */
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
channel_clear_bit(dw, CH_EN, dwc->mask); channel_clear_bit(dw, CH_EN, dwc->mask);
@ -849,7 +885,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
list_splice_init(&dwc->queue, &list); list_splice_init(&dwc->queue, &list);
list_splice_init(&dwc->active_list, &list); list_splice_init(&dwc->active_list, &list);
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
/* Flush all pending and queued descriptors */ /* Flush all pending and queued descriptors */
list_for_each_entry_safe(desc, _desc, &list, desc_node) list_for_each_entry_safe(desc, _desc, &list, desc_node)
@ -873,9 +909,7 @@ dwc_tx_status(struct dma_chan *chan,
ret = dma_async_is_complete(cookie, last_complete, last_used); ret = dma_async_is_complete(cookie, last_complete, last_used);
if (ret != DMA_SUCCESS) { if (ret != DMA_SUCCESS) {
spin_lock_bh(&dwc->lock);
dwc_scan_descriptors(to_dw_dma(chan->device), dwc); dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
spin_unlock_bh(&dwc->lock);
last_complete = dwc->completed; last_complete = dwc->completed;
last_used = chan->cookie; last_used = chan->cookie;
@ -896,10 +930,8 @@ static void dwc_issue_pending(struct dma_chan *chan)
{ {
struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
spin_lock_bh(&dwc->lock);
if (!list_empty(&dwc->queue)) if (!list_empty(&dwc->queue))
dwc_scan_descriptors(to_dw_dma(chan->device), dwc); dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
spin_unlock_bh(&dwc->lock);
} }
static int dwc_alloc_chan_resources(struct dma_chan *chan) static int dwc_alloc_chan_resources(struct dma_chan *chan)
@ -911,6 +943,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
int i; int i;
u32 cfghi; u32 cfghi;
u32 cfglo; u32 cfglo;
unsigned long flags;
dev_vdbg(chan2dev(chan), "alloc_chan_resources\n"); dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
@ -948,16 +981,16 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
* doesn't mean what you think it means), and status writeback. * doesn't mean what you think it means), and status writeback.
*/ */
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
i = dwc->descs_allocated; i = dwc->descs_allocated;
while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) { while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL); desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
if (!desc) { if (!desc) {
dev_info(chan2dev(chan), dev_info(chan2dev(chan),
"only allocated %d descriptors\n", i); "only allocated %d descriptors\n", i);
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
break; break;
} }
@ -969,7 +1002,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
sizeof(desc->lli), DMA_TO_DEVICE); sizeof(desc->lli), DMA_TO_DEVICE);
dwc_desc_put(dwc, desc); dwc_desc_put(dwc, desc);
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
i = ++dwc->descs_allocated; i = ++dwc->descs_allocated;
} }
@ -978,7 +1011,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
channel_set_bit(dw, MASK.BLOCK, dwc->mask); channel_set_bit(dw, MASK.BLOCK, dwc->mask);
channel_set_bit(dw, MASK.ERROR, dwc->mask); channel_set_bit(dw, MASK.ERROR, dwc->mask);
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
dev_dbg(chan2dev(chan), dev_dbg(chan2dev(chan),
"alloc_chan_resources allocated %d descriptors\n", i); "alloc_chan_resources allocated %d descriptors\n", i);
@ -991,6 +1024,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(chan->device); struct dw_dma *dw = to_dw_dma(chan->device);
struct dw_desc *desc, *_desc; struct dw_desc *desc, *_desc;
unsigned long flags;
LIST_HEAD(list); LIST_HEAD(list);
dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n", dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
@ -1001,7 +1035,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
BUG_ON(!list_empty(&dwc->queue)); BUG_ON(!list_empty(&dwc->queue));
BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask); BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
list_splice_init(&dwc->free_list, &list); list_splice_init(&dwc->free_list, &list);
dwc->descs_allocated = 0; dwc->descs_allocated = 0;
@ -1010,7 +1044,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
channel_clear_bit(dw, MASK.BLOCK, dwc->mask); channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
channel_clear_bit(dw, MASK.ERROR, dwc->mask); channel_clear_bit(dw, MASK.ERROR, dwc->mask);
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
list_for_each_entry_safe(desc, _desc, &list, desc_node) { list_for_each_entry_safe(desc, _desc, &list, desc_node) {
dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc); dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
@ -1035,13 +1069,14 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
{ {
struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device); struct dw_dma *dw = to_dw_dma(dwc->chan.device);
unsigned long flags;
if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) { if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n"); dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
return -ENODEV; return -ENODEV;
} }
spin_lock(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
/* assert channel is idle */ /* assert channel is idle */
if (dma_readl(dw, CH_EN) & dwc->mask) { if (dma_readl(dw, CH_EN) & dwc->mask) {
@ -1054,7 +1089,7 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
channel_readl(dwc, LLP), channel_readl(dwc, LLP),
channel_readl(dwc, CTL_HI), channel_readl(dwc, CTL_HI),
channel_readl(dwc, CTL_LO)); channel_readl(dwc, CTL_LO));
spin_unlock(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
return -EBUSY; return -EBUSY;
} }
@ -1069,7 +1104,7 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
channel_set_bit(dw, CH_EN, dwc->mask); channel_set_bit(dw, CH_EN, dwc->mask);
spin_unlock(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
return 0; return 0;
} }
@ -1085,14 +1120,15 @@ void dw_dma_cyclic_stop(struct dma_chan *chan)
{ {
struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device); struct dw_dma *dw = to_dw_dma(dwc->chan.device);
unsigned long flags;
spin_lock(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
channel_clear_bit(dw, CH_EN, dwc->mask); channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask) while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax(); cpu_relax();
spin_unlock(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
} }
EXPORT_SYMBOL(dw_dma_cyclic_stop); EXPORT_SYMBOL(dw_dma_cyclic_stop);
@ -1121,17 +1157,18 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
unsigned int reg_width; unsigned int reg_width;
unsigned int periods; unsigned int periods;
unsigned int i; unsigned int i;
unsigned long flags;
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) { if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
dev_dbg(chan2dev(&dwc->chan), dev_dbg(chan2dev(&dwc->chan),
"queue and/or active list are not empty\n"); "queue and/or active list are not empty\n");
return ERR_PTR(-EBUSY); return ERR_PTR(-EBUSY);
} }
was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags); was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
if (was_cyclic) { if (was_cyclic) {
dev_dbg(chan2dev(&dwc->chan), dev_dbg(chan2dev(&dwc->chan),
"channel already prepared for cyclic DMA\n"); "channel already prepared for cyclic DMA\n");
@ -1245,13 +1282,14 @@ void dw_dma_cyclic_free(struct dma_chan *chan)
struct dw_dma *dw = to_dw_dma(dwc->chan.device); struct dw_dma *dw = to_dw_dma(dwc->chan.device);
struct dw_cyclic_desc *cdesc = dwc->cdesc; struct dw_cyclic_desc *cdesc = dwc->cdesc;
int i; int i;
unsigned long flags;
dev_dbg(chan2dev(&dwc->chan), "cyclic free\n"); dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
if (!cdesc) if (!cdesc)
return; return;
spin_lock_bh(&dwc->lock); spin_lock_irqsave(&dwc->lock, flags);
channel_clear_bit(dw, CH_EN, dwc->mask); channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask) while (dma_readl(dw, CH_EN) & dwc->mask)
@ -1261,7 +1299,7 @@ void dw_dma_cyclic_free(struct dma_chan *chan)
dma_writel(dw, CLEAR.ERROR, dwc->mask); dma_writel(dw, CLEAR.ERROR, dwc->mask);
dma_writel(dw, CLEAR.XFER, dwc->mask); dma_writel(dw, CLEAR.XFER, dwc->mask);
spin_unlock_bh(&dwc->lock); spin_unlock_irqrestore(&dwc->lock, flags);
for (i = 0; i < cdesc->periods; i++) for (i = 0; i < cdesc->periods; i++)
dwc_desc_put(dwc, cdesc->desc[i]); dwc_desc_put(dwc, cdesc->desc[i]);