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authorGuennadi Liakhovetski <g.liakhovetski@gmx.de>2009-03-25 09:13:24 -0700
committerDan Williams <dan.j.williams@intel.com>2009-03-25 09:13:24 -0700
commit8d47bae004f062630f69f7f83d098424252e232d (patch)
tree68379790587eef10926d029ffce74b763175b10c /drivers/dma/ipu
parent234f2df56f5b05756c444edc9879145deddf69f4 (diff)
downloadlinux-bcache-8d47bae004f062630f69f7f83d098424252e232d.tar.zst
dma: i.MX31 IPU DMA robustness improvements
Add DMA error handling to the ISR, move common code fragments to functions, fix scatter-gather element queuing in the ISR, survive channel freeing and re-allocation in a quick succession. Signed-off-by: Guennadi Liakhovetski <lg@denx.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/ipu')
-rw-r--r--drivers/dma/ipu/ipu_idmac.c265
1 files changed, 181 insertions, 84 deletions
diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c
index b759ae9315ba..0a525c450f24 100644
--- a/drivers/dma/ipu/ipu_idmac.c
+++ b/drivers/dma/ipu/ipu_idmac.c
@@ -28,6 +28,9 @@
#define FS_VF_IN_VALID 0x00000002
#define FS_ENC_IN_VALID 0x00000001
+static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan,
+ bool wait_for_stop);
+
/*
* There can be only one, we could allocate it dynamically, but then we'd have
* to add an extra parameter to some functions, and use something as ugly as
@@ -762,9 +765,10 @@ static void ipu_select_buffer(enum ipu_channel channel, int buffer_n)
* function will fail if the buffer is set to ready.
*/
/* Called under spin_lock(_irqsave)(&ichan->lock) */
-static int ipu_update_channel_buffer(enum ipu_channel channel,
+static int ipu_update_channel_buffer(struct idmac_channel *ichan,
int buffer_n, dma_addr_t phyaddr)
{
+ enum ipu_channel channel = ichan->dma_chan.chan_id;
uint32_t reg;
unsigned long flags;
@@ -773,8 +777,8 @@ static int ipu_update_channel_buffer(enum ipu_channel channel,
if (buffer_n == 0) {
reg = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY);
if (reg & (1UL << channel)) {
- spin_unlock_irqrestore(&ipu_data.lock, flags);
- return -EACCES;
+ ipu_ic_disable_task(&ipu_data, channel);
+ ichan->status = IPU_CHANNEL_READY;
}
/* 44.3.3.1.9 - Row Number 1 (WORD1, offset 0) */
@@ -784,8 +788,8 @@ static int ipu_update_channel_buffer(enum ipu_channel channel,
} else {
reg = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY);
if (reg & (1UL << channel)) {
- spin_unlock_irqrestore(&ipu_data.lock, flags);
- return -EACCES;
+ ipu_ic_disable_task(&ipu_data, channel);
+ ichan->status = IPU_CHANNEL_READY;
}
/* Check if double-buffering is already enabled */
@@ -807,6 +811,39 @@ static int ipu_update_channel_buffer(enum ipu_channel channel,
}
/* Called under spin_lock_irqsave(&ichan->lock) */
+static int ipu_submit_buffer(struct idmac_channel *ichan,
+ struct idmac_tx_desc *desc, struct scatterlist *sg, int buf_idx)
+{
+ unsigned int chan_id = ichan->dma_chan.chan_id;
+ struct device *dev = &ichan->dma_chan.dev->device;
+ int ret;
+
+ if (async_tx_test_ack(&desc->txd))
+ return -EINTR;
+
+ /*
+ * On first invocation this shouldn't be necessary, the call to
+ * ipu_init_channel_buffer() above will set addresses for us, so we
+ * could make it conditional on status >= IPU_CHANNEL_ENABLED, but
+ * doing it again shouldn't hurt either.
+ */
+ ret = ipu_update_channel_buffer(ichan, buf_idx,
+ sg_dma_address(sg));
+
+ if (ret < 0) {
+ dev_err(dev, "Updating sg %p on channel 0x%x buffer %d failed!\n",
+ sg, chan_id, buf_idx);
+ return ret;
+ }
+
+ ipu_select_buffer(chan_id, buf_idx);
+ dev_dbg(dev, "Updated sg %p on channel 0x%x buffer %d\n",
+ sg, chan_id, buf_idx);
+
+ return 0;
+}
+
+/* Called under spin_lock_irqsave(&ichan->lock) */
static int ipu_submit_channel_buffers(struct idmac_channel *ichan,
struct idmac_tx_desc *desc)
{
@@ -817,20 +854,10 @@ static int ipu_submit_channel_buffers(struct idmac_channel *ichan,
if (!ichan->sg[i]) {
ichan->sg[i] = sg;
- /*
- * On first invocation this shouldn't be necessary, the
- * call to ipu_init_channel_buffer() above will set
- * addresses for us, so we could make it conditional
- * on status >= IPU_CHANNEL_ENABLED, but doing it again
- * shouldn't hurt either.
- */
- ret = ipu_update_channel_buffer(ichan->dma_chan.chan_id, i,
- sg_dma_address(sg));
+ ret = ipu_submit_buffer(ichan, desc, sg, i);
if (ret < 0)
return ret;
- ipu_select_buffer(ichan->dma_chan.chan_id, i);
-
sg = sg_next(sg);
}
}
@@ -844,19 +871,22 @@ static dma_cookie_t idmac_tx_submit(struct dma_async_tx_descriptor *tx)
struct idmac_channel *ichan = to_idmac_chan(tx->chan);
struct idmac *idmac = to_idmac(tx->chan->device);
struct ipu *ipu = to_ipu(idmac);
+ struct device *dev = &ichan->dma_chan.dev->device;
dma_cookie_t cookie;
unsigned long flags;
+ int ret;
/* Sanity check */
if (!list_empty(&desc->list)) {
/* The descriptor doesn't belong to client */
- dev_err(&ichan->dma_chan.dev->device,
- "Descriptor %p not prepared!\n", tx);
+ dev_err(dev, "Descriptor %p not prepared!\n", tx);
return -EBUSY;
}
mutex_lock(&ichan->chan_mutex);
+ async_tx_clear_ack(tx);
+
if (ichan->status < IPU_CHANNEL_READY) {
struct idmac_video_param *video = &ichan->params.video;
/*
@@ -880,16 +910,7 @@ static dma_cookie_t idmac_tx_submit(struct dma_async_tx_descriptor *tx)
goto out;
}
- /* ipu->lock can be taken under ichan->lock, but not v.v. */
- spin_lock_irqsave(&ichan->lock, flags);
-
- /* submit_buffers() atomically verifies and fills empty sg slots */
- cookie = ipu_submit_channel_buffers(ichan, desc);
-
- spin_unlock_irqrestore(&ichan->lock, flags);
-
- if (cookie < 0)
- goto out;
+ dev_dbg(dev, "Submitting sg %p\n", &desc->sg[0]);
cookie = ichan->dma_chan.cookie;
@@ -899,24 +920,40 @@ static dma_cookie_t idmac_tx_submit(struct dma_async_tx_descriptor *tx)
/* from dmaengine.h: "last cookie value returned to client" */
ichan->dma_chan.cookie = cookie;
tx->cookie = cookie;
+
+ /* ipu->lock can be taken under ichan->lock, but not v.v. */
spin_lock_irqsave(&ichan->lock, flags);
+
list_add_tail(&desc->list, &ichan->queue);
+ /* submit_buffers() atomically verifies and fills empty sg slots */
+ ret = ipu_submit_channel_buffers(ichan, desc);
+
spin_unlock_irqrestore(&ichan->lock, flags);
+ if (ret < 0) {
+ cookie = ret;
+ goto dequeue;
+ }
+
if (ichan->status < IPU_CHANNEL_ENABLED) {
- int ret = ipu_enable_channel(idmac, ichan);
+ ret = ipu_enable_channel(idmac, ichan);
if (ret < 0) {
cookie = ret;
- spin_lock_irqsave(&ichan->lock, flags);
- list_del_init(&desc->list);
- spin_unlock_irqrestore(&ichan->lock, flags);
- tx->cookie = cookie;
- ichan->dma_chan.cookie = cookie;
+ goto dequeue;
}
}
dump_idmac_reg(ipu);
+dequeue:
+ if (cookie < 0) {
+ spin_lock_irqsave(&ichan->lock, flags);
+ list_del_init(&desc->list);
+ spin_unlock_irqrestore(&ichan->lock, flags);
+ tx->cookie = cookie;
+ ichan->dma_chan.cookie = cookie;
+ }
+
out:
mutex_unlock(&ichan->chan_mutex);
@@ -1163,6 +1200,24 @@ static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan,
return 0;
}
+static struct scatterlist *idmac_sg_next(struct idmac_channel *ichan,
+ struct idmac_tx_desc **desc, struct scatterlist *sg)
+{
+ struct scatterlist *sgnew = sg ? sg_next(sg) : NULL;
+
+ if (sgnew)
+ /* next sg-element in this list */
+ return sgnew;
+
+ if ((*desc)->list.next == &ichan->queue)
+ /* No more descriptors on the queue */
+ return NULL;
+
+ /* Fetch next descriptor */
+ *desc = list_entry((*desc)->list.next, struct idmac_tx_desc, list);
+ return (*desc)->sg;
+}
+
/*
* We have several possibilities here:
* current BUF next BUF
@@ -1178,23 +1233,46 @@ static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan,
static irqreturn_t idmac_interrupt(int irq, void *dev_id)
{
struct idmac_channel *ichan = dev_id;
+ struct device *dev = &ichan->dma_chan.dev->device;
unsigned int chan_id = ichan->dma_chan.chan_id;
struct scatterlist **sg, *sgnext, *sgnew = NULL;
/* Next transfer descriptor */
- struct idmac_tx_desc *desc = NULL, *descnew;
+ struct idmac_tx_desc *desc, *descnew;
dma_async_tx_callback callback;
void *callback_param;
bool done = false;
- u32 ready0 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY),
- ready1 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY),
- curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
+ u32 ready0, ready1, curbuf, err;
+ unsigned long flags;
/* IDMAC has cleared the respective BUFx_RDY bit, we manage the buffer */
- pr_debug("IDMAC irq %d\n", irq);
+ dev_dbg(dev, "IDMAC irq %d, buf %d\n", irq, ichan->active_buffer);
+
+ spin_lock_irqsave(&ipu_data.lock, flags);
+
+ ready0 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY);
+ ready1 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY);
+ curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
+ err = idmac_read_ipureg(&ipu_data, IPU_INT_STAT_4);
+
+ if (err & (1 << chan_id)) {
+ idmac_write_ipureg(&ipu_data, 1 << chan_id, IPU_INT_STAT_4);
+ spin_unlock_irqrestore(&ipu_data.lock, flags);
+ /*
+ * Doing this
+ * ichan->sg[0] = ichan->sg[1] = NULL;
+ * you can force channel re-enable on the next tx_submit(), but
+ * this is dirty - think about descriptors with multiple
+ * sg elements.
+ */
+ dev_warn(dev, "NFB4EOF on channel %d, ready %x, %x, cur %x\n",
+ chan_id, ready0, ready1, curbuf);
+ return IRQ_HANDLED;
+ }
+ spin_unlock_irqrestore(&ipu_data.lock, flags);
+
/* Other interrupts do not interfere with this channel */
spin_lock(&ichan->lock);
-
if (unlikely(chan_id != IDMAC_SDC_0 && chan_id != IDMAC_SDC_1 &&
((curbuf >> chan_id) & 1) == ichan->active_buffer)) {
int i = 100;
@@ -1209,19 +1287,23 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
if (!i) {
spin_unlock(&ichan->lock);
- dev_dbg(ichan->dma_chan.device->dev,
+ dev_dbg(dev,
"IRQ on active buffer on channel %x, active "
"%d, ready %x, %x, current %x!\n", chan_id,
ichan->active_buffer, ready0, ready1, curbuf);
return IRQ_NONE;
- }
+ } else
+ dev_dbg(dev,
+ "Buffer deactivated on channel %x, active "
+ "%d, ready %x, %x, current %x, rest %d!\n", chan_id,
+ ichan->active_buffer, ready0, ready1, curbuf, i);
}
if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) ||
(!ichan->active_buffer && (ready0 >> chan_id) & 1)
)) {
spin_unlock(&ichan->lock);
- dev_dbg(ichan->dma_chan.device->dev,
+ dev_dbg(dev,
"IRQ with active buffer still ready on channel %x, "
"active %d, ready %x, %x!\n", chan_id,
ichan->active_buffer, ready0, ready1);
@@ -1229,8 +1311,9 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
}
if (unlikely(list_empty(&ichan->queue))) {
+ ichan->sg[ichan->active_buffer] = NULL;
spin_unlock(&ichan->lock);
- dev_err(ichan->dma_chan.device->dev,
+ dev_err(dev,
"IRQ without queued buffers on channel %x, active %d, "
"ready %x, %x!\n", chan_id,
ichan->active_buffer, ready0, ready1);
@@ -1245,40 +1328,44 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
sg = &ichan->sg[ichan->active_buffer];
sgnext = ichan->sg[!ichan->active_buffer];
+ if (!*sg) {
+ spin_unlock(&ichan->lock);
+ return IRQ_HANDLED;
+ }
+
+ desc = list_entry(ichan->queue.next, struct idmac_tx_desc, list);
+ descnew = desc;
+
+ dev_dbg(dev, "IDMAC irq %d, dma 0x%08x, next dma 0x%08x, current %d, curbuf 0x%08x\n",
+ irq, sg_dma_address(*sg), sgnext ? sg_dma_address(sgnext) : 0, ichan->active_buffer, curbuf);
+
+ /* Find the descriptor of sgnext */
+ sgnew = idmac_sg_next(ichan, &descnew, *sg);
+ if (sgnext != sgnew)
+ dev_err(dev, "Submitted buffer %p, next buffer %p\n", sgnext, sgnew);
+
/*
* if sgnext == NULL sg must be the last element in a scatterlist and
* queue must be empty
*/
if (unlikely(!sgnext)) {
- if (unlikely(sg_next(*sg))) {
- dev_err(ichan->dma_chan.device->dev,
- "Broken buffer-update locking on channel %x!\n",
- chan_id);
- /* We'll let the user catch up */
+ if (!WARN_ON(sg_next(*sg)))
+ dev_dbg(dev, "Underrun on channel %x\n", chan_id);
+ ichan->sg[!ichan->active_buffer] = sgnew;
+
+ if (unlikely(sgnew)) {
+ ipu_submit_buffer(ichan, descnew, sgnew, !ichan->active_buffer);
} else {
- /* Underrun */
+ spin_lock_irqsave(&ipu_data.lock, flags);
ipu_ic_disable_task(&ipu_data, chan_id);
- dev_dbg(ichan->dma_chan.device->dev,
- "Underrun on channel %x\n", chan_id);
+ spin_unlock_irqrestore(&ipu_data.lock, flags);
ichan->status = IPU_CHANNEL_READY;
/* Continue to check for complete descriptor */
}
}
- desc = list_entry(ichan->queue.next, struct idmac_tx_desc, list);
-
- /* First calculate and submit the next sg element */
- if (likely(sgnext))
- sgnew = sg_next(sgnext);
-
- if (unlikely(!sgnew)) {
- /* Start a new scatterlist, if any queued */
- if (likely(desc->list.next != &ichan->queue)) {
- descnew = list_entry(desc->list.next,
- struct idmac_tx_desc, list);
- sgnew = &descnew->sg[0];
- }
- }
+ /* Calculate and submit the next sg element */
+ sgnew = idmac_sg_next(ichan, &descnew, sgnew);
if (unlikely(!sg_next(*sg)) || !sgnext) {
/*
@@ -1291,17 +1378,13 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
*sg = sgnew;
- if (likely(sgnew)) {
- int ret;
-
- ret = ipu_update_channel_buffer(chan_id, ichan->active_buffer,
- sg_dma_address(*sg));
- if (ret < 0)
- dev_err(ichan->dma_chan.device->dev,
- "Failed to update buffer on channel %x buffer %d!\n",
- chan_id, ichan->active_buffer);
- else
- ipu_select_buffer(chan_id, ichan->active_buffer);
+ if (likely(sgnew) &&
+ ipu_submit_buffer(ichan, descnew, sgnew, ichan->active_buffer) < 0) {
+ callback = desc->txd.callback;
+ callback_param = desc->txd.callback_param;
+ spin_unlock(&ichan->lock);
+ callback(callback_param);
+ spin_lock(&ichan->lock);
}
/* Flip the active buffer - even if update above failed */
@@ -1329,13 +1412,20 @@ static void ipu_gc_tasklet(unsigned long arg)
struct idmac_channel *ichan = ipu->channel + i;
struct idmac_tx_desc *desc;
unsigned long flags;
- int j;
+ struct scatterlist *sg;
+ int j, k;
for (j = 0; j < ichan->n_tx_desc; j++) {
desc = ichan->desc + j;
spin_lock_irqsave(&ichan->lock, flags);
if (async_tx_test_ack(&desc->txd)) {
list_move(&desc->list, &ichan->free_list);
+ for_each_sg(desc->sg, sg, desc->sg_len, k) {
+ if (ichan->sg[0] == sg)
+ ichan->sg[0] = NULL;
+ else if (ichan->sg[1] == sg)
+ ichan->sg[1] = NULL;
+ }
async_tx_clear_ack(&desc->txd);
}
spin_unlock_irqrestore(&ichan->lock, flags);
@@ -1471,15 +1561,22 @@ static int idmac_alloc_chan_resources(struct dma_chan *chan)
goto eimap;
ichan->eof_irq = ret;
- ret = request_irq(ichan->eof_irq, idmac_interrupt, 0,
- ichan->eof_name, ichan);
- if (ret < 0)
- goto erirq;
+
+ /*
+ * Important to first disable the channel, because maybe someone
+ * used it before us, e.g., the bootloader
+ */
+ ipu_disable_channel(idmac, ichan, true);
ret = ipu_init_channel(idmac, ichan);
if (ret < 0)
goto eichan;
+ ret = request_irq(ichan->eof_irq, idmac_interrupt, 0,
+ ichan->eof_name, ichan);
+ if (ret < 0)
+ goto erirq;
+
ichan->status = IPU_CHANNEL_INITIALIZED;
dev_dbg(&ichan->dma_chan.dev->device, "Found channel 0x%x, irq %d\n",
@@ -1487,9 +1584,9 @@ static int idmac_alloc_chan_resources(struct dma_chan *chan)
return ret;
-eichan:
- free_irq(ichan->eof_irq, ichan);
erirq:
+ ipu_uninit_channel(idmac, ichan);
+eichan:
ipu_irq_unmap(ichan->dma_chan.chan_id);
eimap:
return ret;