From: Dmitry Osipenko digetx@gmail.com
[ Upstream commit dc161064beb83c668e0f85766b92b1e7ed186e58 ]
Apparently driver was never tested with DMA_PREP_INTERRUPT flag being unset since it completely disables interrupt handling instead of skipping the callbacks invocations, hence putting channel into unusable state.
The flag is always set by all of kernel drivers that use APB DMA, so let's error out in otherwise case for consistency. It won't be difficult to support that case properly if ever will be needed.
Signed-off-by: Dmitry Osipenko digetx@gmail.com Acked-by: Jon Hunter jonathanh@nvidia.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/tegra20-apb-dma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index ef317c90fbe1..79e9593815f1 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -977,8 +977,12 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg( csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; }
- if (flags & DMA_PREP_INTERRUPT) + if (flags & DMA_PREP_INTERRUPT) { csr |= TEGRA_APBDMA_CSR_IE_EOC; + } else { + WARN_ON_ONCE(1); + return NULL; + }
apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
@@ -1120,8 +1124,12 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic( csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; }
- if (flags & DMA_PREP_INTERRUPT) + if (flags & DMA_PREP_INTERRUPT) { csr |= TEGRA_APBDMA_CSR_IE_EOC; + } else { + WARN_ON_ONCE(1); + return NULL; + }
apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;