[PATCH 6/7] fix COH 901 318 memcpy and slave issues
Linus Walleij
linus.walleij at stericsson.com
Thu Feb 18 19:06:03 EST 2010
This patch fixes several issues with the COH 901 318 DMA engine:
- A questionable mechanism for counting the number of interrupts
was removed. There is never more than one interrupt fired for
a transaction in this hardware.
- A debug print was broken to the point that it caused a bug
when swithed on.
- Dynamically configure the slave controller for mem->dev
or dev->mem transfers, this was previously hard-coded in
the channel configurations, but we have a channel which
is actually bidirectionals (MMC/SD) so this doesn't work
out!
- Refactored a bit to get a clearer program flow especially in
the dma_tasklet() and also remove some duplicated code, minor
nitwits, spelling etc.
- Also removed the redundant BUG_ON() located by Julia Lawall
using coccinelle.
Signed-off-by: Linus Walleij <linus.walleij at stericsson.com>
Cc: Julia Lawall <julia at diku.dk>
---
arch/arm/mach-u300/include/mach/coh901318.h | 2 +-
drivers/dma/coh901318.c | 183 ++++++++++++++-------------
drivers/dma/coh901318_lli.c | 19 +--
3 files changed, 105 insertions(+), 99 deletions(-)
diff --git a/arch/arm/mach-u300/include/mach/coh901318.h b/arch/arm/mach-u300/include/mach/coh901318.h
index f4cfee9..b8155b4 100644
--- a/arch/arm/mach-u300/include/mach/coh901318.h
+++ b/arch/arm/mach-u300/include/mach/coh901318.h
@@ -53,7 +53,7 @@ struct coh901318_params {
* struct coh_dma_channel - dma channel base
* @name: ascii name of dma channel
* @number: channel id number
- * @desc_nbr_max: number of preallocated descriptortors
+ * @desc_nbr_max: number of preallocated descriptors
* @priority_high: prio of channel, 0 low otherwise high.
* @param: configuration parameters
* @dev_addr: physical address of periphal connected to channel
diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index 64a9372..372f314 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -39,7 +39,6 @@ struct coh901318_desc {
unsigned int sg_len;
struct coh901318_lli *data;
enum dma_data_direction dir;
- int pending_irqs;
unsigned long flags;
};
@@ -70,9 +69,8 @@ struct coh901318_chan {
struct list_head queue;
struct list_head free;
- unsigned long nbr_active_done;
+ unsigned long nbr_active_done; /* nbr_pending is more appropriate */
unsigned long busy;
- int pending_irqs;
struct coh901318_base *base;
};
@@ -80,18 +78,16 @@ struct coh901318_chan {
static void coh901318_list_print(struct coh901318_chan *cohc,
struct coh901318_lli *lli)
{
- struct coh901318_lli *l;
- dma_addr_t addr = virt_to_phys(lli);
+ struct coh901318_lli *l = lli;
int i = 0;
- while (addr) {
- l = phys_to_virt(addr);
+ while (l) {
dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"
- ", dst 0x%x, link 0x%x link_virt 0x%p\n",
+ ", dst 0x%x, link 0x%x virt_link_addr 0x%p\n",
i, l, l->control, l->src_addr, l->dst_addr,
- l->link_addr, phys_to_virt(l->link_addr));
+ l->link_addr, l->virt_link_addr);
i++;
- addr = l->link_addr;
+ l = l->virt_link_addr;
}
}
@@ -125,7 +121,7 @@ static int coh901318_debugfs_read(struct file *file, char __user *buf,
goto err_kmalloc;
tmp = dev_buf;
- tmp += sprintf(tmp, "DMA -- enable dma channels\n");
+ tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
if (started_channels & (1 << i))
@@ -337,16 +333,22 @@ coh901318_desc_get(struct coh901318_chan *cohc)
* TODO: alloc a pile of descs instead of just one,
* avoid many small allocations.
*/
- desc = kmalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
+ desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
if (desc == NULL)
goto out;
INIT_LIST_HEAD(&desc->node);
+ dma_async_tx_descriptor_init(&desc->desc, &cohc->chan);
} else {
/* Reuse an old desc. */
desc = list_first_entry(&cohc->free,
struct coh901318_desc,
node);
list_del(&desc->node);
+ /* Initialize it a bit so it's not insane */
+ desc->sg = NULL;
+ desc->sg_len = 0;
+ desc->desc.callback = NULL;
+ desc->desc.callback_param = NULL;
}
out:
@@ -364,10 +366,6 @@ static void
coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
{
list_add_tail(&desc->node, &cohc->active);
-
- BUG_ON(cohc->pending_irqs != 0);
-
- cohc->pending_irqs = desc->pending_irqs;
}
static struct coh901318_desc *
@@ -592,6 +590,10 @@ static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
return cohd_que;
}
+/*
+ * This tasklet is called from the interrupt handler to
+ * handle each descriptor (DMA job) that is sent to a channel.
+ */
static void dma_tasklet(unsigned long data)
{
struct coh901318_chan *cohc = (struct coh901318_chan *) data;
@@ -600,55 +602,58 @@ static void dma_tasklet(unsigned long data)
dma_async_tx_callback callback;
void *callback_param;
+ dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d"
+ " nbr_active_done %ld\n", __func__,
+ cohc->id, cohc->nbr_active_done);
+
spin_lock_irqsave(&cohc->lock, flags);
- /* get first active entry from list */
+ /* get first active dexcriptor entry from list */
cohd_fin = coh901318_first_active_get(cohc);
- BUG_ON(cohd_fin->pending_irqs == 0);
-
if (cohd_fin == NULL)
goto err;
- cohd_fin->pending_irqs--;
- cohc->completed = cohd_fin->desc.cookie;
+ /* locate callback to client */
+ callback = cohd_fin->desc.callback;
+ callback_param = cohd_fin->desc.callback_param;
- if (cohc->nbr_active_done == 0)
- return;
+ /* sign this job as completed on the channel */
+ cohc->completed = cohd_fin->desc.cookie;
- if (!cohd_fin->pending_irqs) {
- /* release the lli allocation*/
- coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
- }
+ /* release the lli allocation and remove the descriptor */
+ coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
- dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d pending_irqs %d"
- " nbr_active_done %ld\n", __func__,
- cohc->id, cohc->pending_irqs, cohc->nbr_active_done);
+ /* return desc to free-list */
+ coh901318_desc_remove(cohd_fin);
+ coh901318_desc_free(cohc, cohd_fin);
- /* callback to client */
- callback = cohd_fin->desc.callback;
- callback_param = cohd_fin->desc.callback_param;
-
- if (!cohd_fin->pending_irqs) {
- coh901318_desc_remove(cohd_fin);
+ spin_unlock_irqrestore(&cohc->lock, flags);
- /* return desc to free-list */
- coh901318_desc_free(cohc, cohd_fin);
- }
+ /* Call the callback when we're done */
+ if (callback)
+ callback(callback_param);
- if (cohc->nbr_active_done)
- cohc->nbr_active_done--;
+ spin_lock_irqsave(&cohc->lock, flags);
+ /*
+ * If another interrupt fired while the tasklet was scheduling,
+ * we don't get called twice, so we have this number of active
+ * counter that keep track of the number of IRQs expected to
+ * be handled for this channel. If there happen to be more than
+ * one IRQ to be ack:ed, we simply schedule this tasklet again.
+ */
+ cohc->nbr_active_done--;
if (cohc->nbr_active_done) {
+ dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
+ "came in while we were scheduling this tasklet\n");
if (cohc_chan_conf(cohc)->priority_high)
tasklet_hi_schedule(&cohc->tasklet);
else
tasklet_schedule(&cohc->tasklet);
}
- spin_unlock_irqrestore(&cohc->lock, flags);
- if (callback)
- callback(callback_param);
+ spin_unlock_irqrestore(&cohc->lock, flags);
return;
@@ -667,16 +672,17 @@ static void dma_tc_handle(struct coh901318_chan *cohc)
if (!cohc->allocated)
return;
- BUG_ON(cohc->pending_irqs == 0);
+ spin_lock(&cohc->lock);
- cohc->pending_irqs--;
cohc->nbr_active_done++;
- if (cohc->pending_irqs == 0 && coh901318_queue_start(cohc) == NULL)
+ if (coh901318_queue_start(cohc) == NULL)
cohc->busy = 0;
BUG_ON(list_empty(&cohc->active));
+ spin_unlock(&cohc->lock);
+
if (cohc_chan_conf(cohc)->priority_high)
tasklet_hi_schedule(&cohc->tasklet);
else
@@ -870,6 +876,7 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
struct coh901318_chan *cohc = to_coh901318_chan(chan);
int lli_len;
u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
+ int ret;
spin_lock_irqsave(&cohc->lock, flg);
@@ -890,22 +897,19 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
if (data == NULL)
goto err;
- cohd = coh901318_desc_get(cohc);
- cohd->sg = NULL;
- cohd->sg_len = 0;
- cohd->data = data;
-
- cohd->pending_irqs =
- coh901318_lli_fill_memcpy(
- &cohc->base->pool, data, src, size, dest,
- cohc_chan_param(cohc)->ctrl_lli_chained,
- ctrl_last);
- cohd->flags = flags;
+ ret = coh901318_lli_fill_memcpy(
+ &cohc->base->pool, data, src, size, dest,
+ cohc_chan_param(cohc)->ctrl_lli_chained,
+ ctrl_last);
+ if (ret)
+ goto err;
COH_DBG(coh901318_list_print(cohc, data));
- dma_async_tx_descriptor_init(&cohd->desc, chan);
-
+ /* Pick a descriptor to handle this transfer */
+ cohd = coh901318_desc_get(cohc);
+ cohd->data = data;
+ cohd->flags = flags;
cohd->desc.tx_submit = coh901318_tx_submit;
spin_unlock_irqrestore(&cohc->lock, flg);
@@ -924,6 +928,7 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
struct coh901318_chan *cohc = to_coh901318_chan(chan);
struct coh901318_lli *data;
struct coh901318_desc *cohd;
+ const struct coh901318_params *params;
struct scatterlist *sg;
int len = 0;
int size;
@@ -931,7 +936,9 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
+ u32 config;
unsigned long flg;
+ int ret;
if (!sgl)
goto out;
@@ -947,15 +954,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
/* Trigger interrupt after last lli */
ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
- cohd = coh901318_desc_get(cohc);
- cohd->sg = NULL;
- cohd->sg_len = 0;
- cohd->dir = direction;
+ params = cohc_chan_param(cohc);
+ config = params->config;
if (direction == DMA_TO_DEVICE) {
u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;
+ config |= COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY;
ctrl_chained |= tx_flags;
ctrl_last |= tx_flags;
ctrl |= tx_flags;
@@ -963,15 +969,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;
+ config |= COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY;
ctrl_chained |= rx_flags;
ctrl_last |= rx_flags;
ctrl |= rx_flags;
} else
goto err_direction;
- dma_async_tx_descriptor_init(&cohd->desc, chan);
-
- cohd->desc.tx_submit = coh901318_tx_submit;
+ coh901318_set_conf(cohc, config);
/* The dma only supports transmitting packages up to
@@ -994,32 +999,37 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
len += factor;
}
+ pr_debug("Allocate %d lli:s for this transfer\n", len);
data = coh901318_lli_alloc(&cohc->base->pool, len);
if (data == NULL)
goto err_dma_alloc;
/* initiate allocated data list */
- cohd->pending_irqs =
- coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
- cohc_dev_addr(cohc),
- ctrl_chained,
- ctrl,
- ctrl_last,
- direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
- cohd->data = data;
-
- cohd->flags = flags;
+ ret = coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
+ cohc_dev_addr(cohc),
+ ctrl_chained,
+ ctrl,
+ ctrl_last,
+ direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
+ if (ret)
+ goto err_lli_fill;
COH_DBG(coh901318_list_print(cohc, data));
+ /* Pick a descriptor to handle this transfer */
+ cohd = coh901318_desc_get(cohc);
+ cohd->dir = direction;
+ cohd->flags = flags;
+ cohd->desc.tx_submit = coh901318_tx_submit;
+ cohd->data = data;
+
spin_unlock_irqrestore(&cohc->lock, flg);
return &cohd->desc;
+ err_lli_fill:
err_dma_alloc:
err_direction:
- coh901318_desc_remove(cohd);
- coh901318_desc_free(cohc, cohd);
spin_unlock_irqrestore(&cohc->lock, flg);
out:
return NULL;
@@ -1092,9 +1102,8 @@ coh901318_terminate_all(struct dma_chan *chan)
/* release the lli allocation*/
coh901318_lli_free(&cohc->base->pool, &cohd->data);
- coh901318_desc_remove(cohd);
-
/* return desc to free-list */
+ coh901318_desc_remove(cohd);
coh901318_desc_free(cohc, cohd);
}
@@ -1102,16 +1111,14 @@ coh901318_terminate_all(struct dma_chan *chan)
/* release the lli allocation*/
coh901318_lli_free(&cohc->base->pool, &cohd->data);
- coh901318_desc_remove(cohd);
-
/* return desc to free-list */
+ coh901318_desc_remove(cohd);
coh901318_desc_free(cohc, cohd);
}
cohc->nbr_active_done = 0;
cohc->busy = 0;
- cohc->pending_irqs = 0;
spin_unlock_irqrestore(&cohc->lock, flags);
}
@@ -1138,7 +1145,6 @@ void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
spin_lock_init(&cohc->lock);
- cohc->pending_irqs = 0;
cohc->nbr_active_done = 0;
cohc->busy = 0;
INIT_LIST_HEAD(&cohc->free);
@@ -1254,12 +1260,17 @@ static int __init coh901318_probe(struct platform_device *pdev)
base->dma_memcpy.device_issue_pending = coh901318_issue_pending;
base->dma_memcpy.device_terminate_all = coh901318_terminate_all;
base->dma_memcpy.dev = &pdev->dev;
+ /*
+ * This controller can only access address at even 32bit boundaries,
+ * i.e. 2^2
+ */
+ base->dma_memcpy.copy_align = 2;
err = dma_async_device_register(&base->dma_memcpy);
if (err)
goto err_register_memcpy;
- dev_dbg(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
+ dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
(u32) base->virtbase);
return err;
diff --git a/drivers/dma/coh901318_lli.c b/drivers/dma/coh901318_lli.c
index f5120f2..3679624 100644
--- a/drivers/dma/coh901318_lli.c
+++ b/drivers/dma/coh901318_lli.c
@@ -74,6 +74,8 @@ coh901318_lli_alloc(struct coh901318_pool *pool, unsigned int len)
lli = head;
lli->phy_this = phy;
+ lli->link_addr = 0x00000000;
+ lli->virt_link_addr = 0x00000000U;
for (i = 1; i < len; i++) {
lli_prev = lli;
@@ -85,13 +87,13 @@ coh901318_lli_alloc(struct coh901318_pool *pool, unsigned int len)
DEBUGFS_POOL_COUNTER_ADD(pool, 1);
lli->phy_this = phy;
+ lli->link_addr = 0x00000000;
+ lli->virt_link_addr = 0x00000000U;
lli_prev->link_addr = phy;
lli_prev->virt_link_addr = lli;
}
- lli->link_addr = 0x00000000U;
-
spin_unlock(&pool->lock);
return head;
@@ -166,8 +168,7 @@ coh901318_lli_fill_memcpy(struct coh901318_pool *pool,
lli->src_addr = src;
lli->dst_addr = dst;
- /* One irq per single transfer */
- return 1;
+ return 0;
}
int
@@ -223,8 +224,7 @@ coh901318_lli_fill_single(struct coh901318_pool *pool,
lli->src_addr = src;
lli->dst_addr = dst;
- /* One irq per single transfer */
- return 1;
+ return 0;
}
int
@@ -240,7 +240,6 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
u32 ctrl_sg;
dma_addr_t src = 0;
dma_addr_t dst = 0;
- int nbr_of_irq = 0;
u32 bytes_to_transfer;
u32 elem_size;
@@ -269,9 +268,6 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
ctrl_sg = ctrl ? ctrl : ctrl_last;
- if ((ctrl_sg & ctrl_irq_mask))
- nbr_of_irq++;
-
if (dir == DMA_TO_DEVICE)
/* increment source address */
src = sg_dma_address(sg);
@@ -310,8 +306,7 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
}
spin_unlock(&pool->lock);
- /* There can be many IRQs per sg transfer */
- return nbr_of_irq;
+ return 0;
err:
spin_unlock(&pool->lock);
return -EINVAL;
--
1.6.6
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