To support multi-size buffers in the mx3_camera V4L2 driver we have to be
able to stop DMA on a channel without releasing descriptors and completely
halting the hardware. Use the DMA_PAUSE control to implement this mode.
Signed-off-by: Guennadi Liakhovetski <g.liakhovet...@gmx.de>
Acked-by: Vinod Koul <vinod.k...@linux.intel.com>
Cc: Hans Verkuil <hverk...@xs4all.nl>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Marek Szyprowski <m.szyprow...@samsung.com>
Cc: Mauro Carvalho Chehab <mche...@infradead.org>
Cc: Pawel Osciak <pa...@osciak.com>
Cc: Sakari Ailus <sakari.ai...@maxwell.research.nokia.com>
---
drivers/dma/ipu/ipu_idmac.c | 65 +++++++++++++++++++++++++++---------------
1 files changed, 42 insertions(+), 23 deletions(-)
diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c
index c1a125e..42cdf1c 100644
--- a/drivers/dma/ipu/ipu_idmac.c
+++ b/drivers/dma/ipu/ipu_idmac.c
@@ -1306,6 +1306,7 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
ipu_submit_buffer(ichan, descnew, sgnew, ichan->active_buffer) < 0)
{
callback = descnew->txd.callback;
callback_param = descnew->txd.callback_param;
+ list_del_init(&descnew->list);
spin_unlock(&ichan->lock);
if (callback)
callback(callback_param);
@@ -1427,39 +1428,58 @@ static int __idmac_control(struct dma_chan *chan, enum
dma_ctrl_cmd cmd,
{
struct idmac_channel *ichan = to_idmac_chan(chan);
struct idmac *idmac = to_idmac(chan->device);
+ struct ipu *ipu = to_ipu(idmac);
+ struct list_head *list, *tmp;
unsigned long flags;
int i;
- /* Only supports DMA_TERMINATE_ALL */
- if (cmd != DMA_TERMINATE_ALL)
- return -ENXIO;
+ switch (cmd) {
+ case DMA_PAUSE:
+ spin_lock_irqsave(&ipu->lock, flags);
+ ipu_ic_disable_task(ipu, chan->chan_id);
- ipu_disable_channel(idmac, ichan,
- ichan->status >= IPU_CHANNEL_ENABLED);
+ /* Return all descriptors into "prepared" state */
+ list_for_each_safe(list, tmp, &ichan->queue)
+ list_del_init(list);
- tasklet_disable(&to_ipu(idmac)->tasklet);
+ ichan->sg[0] = NULL;
+ ichan->sg[1] = NULL;
- /* ichan->queue is modified in ISR, have to spinlock */
- spin_lock_irqsave(&ichan->lock, flags);
- list_splice_init(&ichan->queue, &ichan->free_list);
+ spin_unlock_irqrestore(&ipu->lock, flags);
- if (ichan->desc)
- for (i = 0; i < ichan->n_tx_desc; i++) {
- struct idmac_tx_desc *desc = ichan->desc + i;
- if (list_empty(&desc->list))
- /* Descriptor was prepared, but not submitted */
- list_add(&desc->list, &ichan->free_list);
+ ichan->status = IPU_CHANNEL_INITIALIZED;
+ break;
+ case DMA_TERMINATE_ALL:
+ ipu_disable_channel(idmac, ichan,
+ ichan->status >= IPU_CHANNEL_ENABLED);
- async_tx_clear_ack(&desc->txd);
- }
+ tasklet_disable(&ipu->tasklet);
- ichan->sg[0] = NULL;
- ichan->sg[1] = NULL;
- spin_unlock_irqrestore(&ichan->lock, flags);
+ /* ichan->queue is modified in ISR, have to spinlock */
+ spin_lock_irqsave(&ichan->lock, flags);
+ list_splice_init(&ichan->queue, &ichan->free_list);
- tasklet_enable(&to_ipu(idmac)->tasklet);
+ if (ichan->desc)
+ for (i = 0; i < ichan->n_tx_desc; i++) {
+ struct idmac_tx_desc *desc = ichan->desc + i;
+ if (list_empty(&desc->list))
+ /* Descriptor was prepared, but not
submitted */
+ list_add(&desc->list,
&ichan->free_list);
- ichan->status = IPU_CHANNEL_INITIALIZED;
+ async_tx_clear_ack(&desc->txd);
+ }
+
+ ichan->sg[0] = NULL;
+ ichan->sg[1] = NULL;
+ spin_unlock_irqrestore(&ichan->lock, flags);
+
+ tasklet_enable(&ipu->tasklet);
+
+ ichan->status = IPU_CHANNEL_INITIALIZED;
+ break;
+ default:
+ return -ENOSYS;
+ }
return 0;
}
@@ -1662,7 +1682,6 @@ static void __exit ipu_idmac_exit(struct ipu *ipu)
struct idmac_channel *ichan = ipu->channel + i;
idmac_control(&ichan->dma_chan, DMA_TERMINATE_ALL, 0);
- idmac_prep_slave_sg(&ichan->dma_chan, NULL, 0, DMA_NONE, 0);
}
dma_async_device_unregister(&idmac->dma);
--
1.7.2.5
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