diff options
| -rw-r--r-- | drivers/dma/dw/core.c | 51 |
1 files changed, 44 insertions, 7 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 11e269a31a09..b341a6f1b043 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -622,12 +622,10 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, struct dw_desc *prev; struct dw_desc *first; u32 ctllo, ctlhi; - u8 m_master = dwc->dws.m_master; - u8 lms = DWC_LLP_LMS(m_master); + u8 lms = DWC_LLP_LMS(dwc->dws.m_master); dma_addr_t reg; unsigned int reg_width; unsigned int mem_width; - unsigned int data_width = dw->pdata->data_width[m_master]; unsigned int i; struct scatterlist *sg; size_t total_len = 0; @@ -661,7 +659,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, mem = sg_dma_address(sg); len = sg_dma_len(sg); - mem_width = __ffs(data_width | mem | len); + mem_width = __ffs(sconfig->src_addr_width | mem | len); slave_sg_todev_fill_desc: desc = dwc_desc_get(dwc); @@ -721,7 +719,7 @@ slave_sg_fromdev_fill_desc: lli_write(desc, sar, reg); lli_write(desc, dar, mem); lli_write(desc, ctlhi, ctlhi); - mem_width = __ffs(data_width | mem); + mem_width = __ffs(sconfig->dst_addr_width | mem); lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width)); desc->len = dlen; @@ -813,6 +811,41 @@ static int dwc_verify_p_buswidth(struct dma_chan *chan) return 0; } +static int dwc_verify_m_buswidth(struct dma_chan *chan) +{ + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); + struct dw_dma *dw = to_dw_dma(chan->device); + u32 reg_width, reg_burst, mem_width; + + mem_width = dw->pdata->data_width[dwc->dws.m_master]; + + /* + * It's possible to have a data portion locked in the DMA FIFO in case + * of the channel suspension. Subsequent channel disabling will cause + * that data silent loss. In order to prevent that maintain the src and + * dst transfer widths coherency by means of the relation: + * (CTLx.SRC_TR_WIDTH * CTLx.SRC_MSIZE >= CTLx.DST_TR_WIDTH) + * Look for the details in the commit message that brings this change. + * + * Note the DMA configs utilized in the calculations below must have + * been verified to have correct values by this method call. + */ + if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV) { + reg_width = dwc->dma_sconfig.dst_addr_width; + if (mem_width < reg_width) + return -EINVAL; + + dwc->dma_sconfig.src_addr_width = mem_width; + } else if (dwc->dma_sconfig.direction == DMA_DEV_TO_MEM) { + reg_width = dwc->dma_sconfig.src_addr_width; + reg_burst = rounddown_pow_of_two(dwc->dma_sconfig.src_maxburst); + + dwc->dma_sconfig.dst_addr_width = min(mem_width, reg_width * reg_burst); + } + + return 0; +} + static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig) { struct dw_dma_chan *dwc = to_dw_dma_chan(chan); @@ -822,14 +855,18 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig) memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig)); dwc->dma_sconfig.src_maxburst = - clamp(dwc->dma_sconfig.src_maxburst, 0U, dwc->max_burst); + clamp(dwc->dma_sconfig.src_maxburst, 1U, dwc->max_burst); dwc->dma_sconfig.dst_maxburst = - clamp(dwc->dma_sconfig.dst_maxburst, 0U, dwc->max_burst); + clamp(dwc->dma_sconfig.dst_maxburst, 1U, dwc->max_burst); ret = dwc_verify_p_buswidth(chan); if (ret) return ret; + ret = dwc_verify_m_buswidth(chan); + if (ret) + return ret; + dw->encode_maxburst(dwc, &dwc->dma_sconfig.src_maxburst); dw->encode_maxburst(dwc, &dwc->dma_sconfig.dst_maxburst); |