diff options
| author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2013-04-09 16:33:06 +0200 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2013-04-10 07:03:30 +0200 |
| commit | 765024697807ad1e1cac332aa891253ca4a339da (patch) | |
| tree | 11f93e7ecd27a427b6e5253f5fca8b32d883d830 /drivers/dma | |
| parent | DMA: PL330: Add check if device tree compatible (diff) | |
| download | linux-765024697807ad1e1cac332aa891253ca4a339da.tar.xz linux-765024697807ad1e1cac332aa891253ca4a339da.zip | |
dmaengine: omap-dma: Start DMA without delay for cyclic channels
cyclic DMA is only used by audio which needs DMA to be started without a
delay.
If the DMA for audio is started using the tasklet we experience random
channel switch (to be more precise: channel shift).
Reported-by: Peter Meerwald <pmeerw@pmeerw.net>
CC: stable@vger.kernel.org # v3.7+
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/omap-dma.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index c4b4fd2acc42..08b43bf37158 100644 --- a/drivers/dma/omap-dma.c +++ b/drivers/dma/omap-dma.c @@ -276,12 +276,20 @@ static void omap_dma_issue_pending(struct dma_chan *chan) spin_lock_irqsave(&c->vc.lock, flags); if (vchan_issue_pending(&c->vc) && !c->desc) { - struct omap_dmadev *d = to_omap_dma_dev(chan->device); - spin_lock(&d->lock); - if (list_empty(&c->node)) - list_add_tail(&c->node, &d->pending); - spin_unlock(&d->lock); - tasklet_schedule(&d->task); + /* + * c->cyclic is used only by audio and in this case the DMA need + * to be started without delay. + */ + if (!c->cyclic) { + struct omap_dmadev *d = to_omap_dma_dev(chan->device); + spin_lock(&d->lock); + if (list_empty(&c->node)) + list_add_tail(&c->node, &d->pending); + spin_unlock(&d->lock); + tasklet_schedule(&d->task); + } else { + omap_dma_start_desc(c); + } } spin_unlock_irqrestore(&c->vc.lock, flags); } |