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authorPierre-Yves MORDRET <pierre-yves.mordret@st.com>2018-09-11 09:31:16 +0200
committerVinod Koul <vkoul@kernel.org>2018-10-02 20:32:15 +0530
commitcc832dc8e32785a730ba07c3a357e17c201a5df8 (patch)
tree029a27817f27239a472b4837bbbae98efd408d15 /drivers/dma
parent5b394b2ddf0347bef56e50c69a58773c94343ff3 (diff)
dmaengine: stm32-dma: check whether length is aligned on FIFO threshold
When a period length is not multiple of FIFO some data may be stuck within FIFO. Burst/FIFO Threshold/Period or buffer length check has to be hardened In any case DMA will grant any request from client but will degraded any parameters whether awkward. Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/stm32-dma.c20
1 files changed, 6 insertions, 14 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 379e8d534e61..4903a408fc14 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -308,20 +308,12 @@ static bool stm32_dma_fifo_threshold_is_allowed(u32 burst, u32 threshold,
static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
{
- switch (threshold) {
- case STM32_DMA_FIFO_THRESHOLD_FULL:
- if (buf_len >= STM32_DMA_MAX_BURST)
- return true;
- else
- return false;
- case STM32_DMA_FIFO_THRESHOLD_HALFFULL:
- if (buf_len >= STM32_DMA_MAX_BURST / 2)
- return true;
- else
- return false;
- default:
- return false;
- }
+ /*
+ * Buffer or period length has to be aligned on FIFO depth.
+ * Otherwise bytes may be stuck within FIFO at buffer or period
+ * length.
+ */
+ return ((buf_len % ((threshold + 1) * 4)) == 0);
}
static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,