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@xxxxx>
> ---
> 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?
--
~Vinod
