diff options
| author | Matthias Reichl <hias@horus.com> | 2017-02-20 20:01:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-29 13:00:31 +0200 |
| commit | 25c7794ed046e9190200983e330f221170cb2b0a (patch) | |
| tree | ff9c5d5076cdf9bf8ae247ead0a95ae82004b831 | |
| parent | 81135c71bde3346a39cec07b4a0b5de1f5fabdf1 (diff) | |
dmaengine: bcm2835: Fix cyclic DMA period splitting
commit 2201ac6129fa162ac24da089a034bb0971648ebb upstream.
The code responsible for splitting periods into chunks that
can be handled by the DMA controller missed to update total_len,
the number of bytes processed in the current period, when there
are more chunks to follow.
Therefore total_len was stuck at 0 and the code didn't work at all.
This resulted in a wrong control block layout and audio issues because
the cyclic DMA callback wasn't executing on period boundaries.
Fix this by adding the missing total_len update.
Signed-off-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Tested-by: Clive Messer <clive.messer@digitaldreamtime.co.uk>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/dma/bcm2835-dma.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index e18dc596cf24..6204cc32d09c 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -251,8 +251,11 @@ static void bcm2835_dma_create_cb_set_length( */ /* have we filled in period_length yet? */ - if (*total_len + control_block->length < period_len) + if (*total_len + control_block->length < period_len) { + /* update number of bytes in this period so far */ + *total_len += control_block->length; return; + } /* calculate the length that remains to reach period_length */ control_block->length = period_len - *total_len; |