From e0ebdbdcb42a66f49b7587dc50cc6f528ec55cad Mon Sep 17 00:00:00 2001 From: Amelie Delaunay Date: Fri, 20 Nov 2020 15:33:19 +0100 Subject: [PATCH] dmaengine: stm32-dma: take address into account when computing max width DMA_SxPAR or DMA_SxM0AR/M1AR registers have to be aligned on PSIZE or MSIZE respectively. This means that bus width needs to be forced to 1 byte when computed width is not aligned with address. Signed-off-by: Amelie Delaunay Link: https://lore.kernel.org/r/20201120143320.30367-4-amelie.delaunay@st.com Signed-off-by: Vinod Koul --- drivers/dma/stm32-dma.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index 62501e5..f54ecb1 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -264,9 +264,11 @@ static int stm32_dma_get_width(struct stm32_dma_chan *chan, } static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len, + dma_addr_t buf_addr, u32 threshold) { enum dma_slave_buswidth max_width; + u64 addr = buf_addr; if (threshold == STM32_DMA_FIFO_THRESHOLD_FULL) max_width = DMA_SLAVE_BUSWIDTH_4_BYTES; @@ -277,6 +279,9 @@ static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len, max_width > DMA_SLAVE_BUSWIDTH_1_BYTE) max_width = max_width >> 1; + if (do_div(addr, max_width)) + max_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + return max_width; } @@ -707,7 +712,7 @@ static void stm32_dma_issue_pending(struct dma_chan *c) static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan, enum dma_transfer_direction direction, enum dma_slave_buswidth *buswidth, - u32 buf_len) + u32 buf_len, dma_addr_t buf_addr) { enum dma_slave_buswidth src_addr_width, dst_addr_width; int src_bus_width, dst_bus_width; @@ -739,7 +744,8 @@ static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan, return dst_burst_size; /* Set memory data size */ - src_addr_width = stm32_dma_get_max_width(buf_len, fifoth); + src_addr_width = stm32_dma_get_max_width(buf_len, buf_addr, + fifoth); chan->mem_width = src_addr_width; src_bus_width = stm32_dma_get_width(chan, src_addr_width); if (src_bus_width < 0) @@ -788,7 +794,8 @@ static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan, return src_burst_size; /* Set memory data size */ - dst_addr_width = stm32_dma_get_max_width(buf_len, fifoth); + dst_addr_width = stm32_dma_get_max_width(buf_len, buf_addr, + fifoth); chan->mem_width = dst_addr_width; dst_bus_width = stm32_dma_get_width(chan, dst_addr_width); if (dst_bus_width < 0) @@ -876,7 +883,8 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg( for_each_sg(sgl, sg, sg_len, i) { ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, - sg_dma_len(sg)); + sg_dma_len(sg), + sg_dma_address(sg)); if (ret < 0) goto err; @@ -944,7 +952,8 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic( return NULL; } - ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len); + ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len, + buf_addr); if (ret < 0) return NULL; -- 2.7.4