| Message ID | 20200419164912.670973-4-lkundrak@v3.sk (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | dmaengine: mmp_tdma: Make the driver actually work | expand |
On 19-04-20, 18:49, Lubomir Rintel wrote: > We only support DMA_DEV_TO_MEM and DMA_MEM_TO_DEV. Let's not do > undefined things with other values and reject them. > > Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> > --- > drivers/dma/mmp_tdma.c | 37 ++++++++++++++++++++++++++++--------- > 1 file changed, 28 insertions(+), 9 deletions(-) > > diff --git a/drivers/dma/mmp_tdma.c b/drivers/dma/mmp_tdma.c > index d559bb4d6a31d..d574641791598 100644 > --- a/drivers/dma/mmp_tdma.c > +++ b/drivers/dma/mmp_tdma.c > @@ -207,10 +207,17 @@ static int mmp_tdma_config_chan(struct dma_chan *chan) > > mmp_tdma_disable_chan(chan); > > - if (tdmac->dir == DMA_MEM_TO_DEV) > - tdcr = TDCR_DSTDIR_ADDR_HOLD | TDCR_SRCDIR_ADDR_INC; > - else if (tdmac->dir == DMA_DEV_TO_MEM) > + switch (tdmac->dir) { > + case DMA_DEV_TO_MEM: > tdcr = TDCR_SRCDIR_ADDR_HOLD | TDCR_DSTDIR_ADDR_INC; > + break; > + case DMA_MEM_TO_DEV: > + tdcr = TDCR_DSTDIR_ADDR_HOLD | TDCR_SRCDIR_ADDR_INC; > + break; > + default: > + dev_err(tdmac->dev, "invalid transfer direction\n"); > + return -EINVAL; > + } You can use macros is_slave_direction() to validate > if (tdmac->type == MMP_AUD_TDMA) { > tdcr |= TDCR_PACKMOD; > @@ -455,12 +462,18 @@ static struct dma_async_tx_descriptor *mmp_tdma_prep_dma_cyclic( > desc->nxt_desc = tdmac->desc_arr_phys + > sizeof(*desc) * (i + 1); > It would make more sense to use is_slave_direction() and reject up early in the function and proceed only when good :) > - if (direction == DMA_MEM_TO_DEV) { > - desc->src_addr = dma_addr; > - desc->dst_addr = tdmac->dev_addr; > - } else { > + switch (direction) { > + case DMA_DEV_TO_MEM: > desc->src_addr = tdmac->dev_addr; > desc->dst_addr = dma_addr; > + break; > + case DMA_MEM_TO_DEV: > + desc->src_addr = dma_addr; > + desc->dst_addr = tdmac->dev_addr; > + break; > + default: > + dev_err(tdmac->dev, "invalid transfer direction\n"); > + goto err_out; > } > desc->byte_cnt = period_len; > dma_addr += period_len; > @@ -510,14 +523,20 @@ static int mmp_tdma_config_write(struct dma_chan *chan, > { > struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan); > > - if (dir == DMA_DEV_TO_MEM) { > + switch (dir) { > + case DMA_DEV_TO_MEM: > tdmac->dev_addr = dmaengine_cfg->src_addr; > tdmac->burst_sz = dmaengine_cfg->src_maxburst; > tdmac->buswidth = dmaengine_cfg->src_addr_width; > - } else { > + break; > + case DMA_MEM_TO_DEV: > tdmac->dev_addr = dmaengine_cfg->dst_addr; > tdmac->burst_sz = dmaengine_cfg->dst_maxburst; > tdmac->buswidth = dmaengine_cfg->dst_addr_width; > + break; > + default: > + dev_err(tdmac->dev, "invalid transfer direction\n"); > + return -EINVAL; is this required, if you have checked in all _prep() fns then you are guaranteed that this will never hit, right?
diff --git a/drivers/dma/mmp_tdma.c b/drivers/dma/mmp_tdma.c index d559bb4d6a31d..d574641791598 100644 --- a/drivers/dma/mmp_tdma.c +++ b/drivers/dma/mmp_tdma.c @@ -207,10 +207,17 @@ static int mmp_tdma_config_chan(struct dma_chan *chan) mmp_tdma_disable_chan(chan); - if (tdmac->dir == DMA_MEM_TO_DEV) - tdcr = TDCR_DSTDIR_ADDR_HOLD | TDCR_SRCDIR_ADDR_INC; - else if (tdmac->dir == DMA_DEV_TO_MEM) + switch (tdmac->dir) { + case DMA_DEV_TO_MEM: tdcr = TDCR_SRCDIR_ADDR_HOLD | TDCR_DSTDIR_ADDR_INC; + break; + case DMA_MEM_TO_DEV: + tdcr = TDCR_DSTDIR_ADDR_HOLD | TDCR_SRCDIR_ADDR_INC; + break; + default: + dev_err(tdmac->dev, "invalid transfer direction\n"); + return -EINVAL; + } if (tdmac->type == MMP_AUD_TDMA) { tdcr |= TDCR_PACKMOD; @@ -455,12 +462,18 @@ static struct dma_async_tx_descriptor *mmp_tdma_prep_dma_cyclic( desc->nxt_desc = tdmac->desc_arr_phys + sizeof(*desc) * (i + 1); - if (direction == DMA_MEM_TO_DEV) { - desc->src_addr = dma_addr; - desc->dst_addr = tdmac->dev_addr; - } else { + switch (direction) { + case DMA_DEV_TO_MEM: desc->src_addr = tdmac->dev_addr; desc->dst_addr = dma_addr; + break; + case DMA_MEM_TO_DEV: + desc->src_addr = dma_addr; + desc->dst_addr = tdmac->dev_addr; + break; + default: + dev_err(tdmac->dev, "invalid transfer direction\n"); + goto err_out; } desc->byte_cnt = period_len; dma_addr += period_len; @@ -510,14 +523,20 @@ static int mmp_tdma_config_write(struct dma_chan *chan, { struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan); - if (dir == DMA_DEV_TO_MEM) { + switch (dir) { + case DMA_DEV_TO_MEM: tdmac->dev_addr = dmaengine_cfg->src_addr; tdmac->burst_sz = dmaengine_cfg->src_maxburst; tdmac->buswidth = dmaengine_cfg->src_addr_width; - } else { + break; + case DMA_MEM_TO_DEV: tdmac->dev_addr = dmaengine_cfg->dst_addr; tdmac->burst_sz = dmaengine_cfg->dst_maxburst; tdmac->buswidth = dmaengine_cfg->dst_addr_width; + break; + default: + dev_err(tdmac->dev, "invalid transfer direction\n"); + return -EINVAL; } tdmac->dir = dir;
We only support DMA_DEV_TO_MEM and DMA_MEM_TO_DEV. Let's not do undefined things with other values and reject them. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> --- drivers/dma/mmp_tdma.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-)