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>
This commit is contained in:
Guennadi Liakhovetski 2009-03-25 09:13:24 -07:00 committed by Dan Williams
parent 234f2df56f
commit 8d47bae004

View File

@ -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 */
@ -806,6 +810,39 @@ static int ipu_update_channel_buffer(enum ipu_channel channel,
return 0;
}
/* 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;