[PATCH v1 1/2] dmaengine: stm32-mdma: align TLEN and buffer length on burst

From: Pierre-Yves MORDRET
Date: Tue Mar 13 2018 - 13:16:35 EST


Both buffer Transfer Length (TLEN if any) and transfer size have to be
aligned on burst size (burst beats*bus width).

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx>
---
Version history:
v1:
* Initial
---
---
drivers/dma/stm32-mdma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index daa1602..fbcffa2 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -413,7 +413,7 @@ static u32 stm32_mdma_get_best_burst(u32 buf_len, u32 tlen, u32 max_burst,
u32 best_burst = max_burst;
u32 burst_len = best_burst * width;

- while ((burst_len > 0) && (tlen % burst_len)) {
+ while ((burst_len > 0) && (((tlen | buf_len) & (burst_len - 1)) != 0)) {
best_burst = best_burst >> 1;
burst_len = best_burst * width;
}
--
2.7.4