Re: [PATCH 2/5] dmaengine: omap-dma: Implement protection for invalid max_burst

Vinod Koul
2017-09-21T17:32:06Z

On Tue, Sep 12, 2017 at 01:44:21PM +0300, Peter Ujfalusi wrote:
> Set the device's max_burst to 16777215 (EN is 24bit unsigned value) so
> clients can take this into consideration when setting up the trasnfer.

ditto :D

>
> During slave transfer preparation check if the requested maxburst is valid.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---
> drivers/dma/omap-dma.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
> index 8c1665c8fe33..f6dd849159d8 100644
> --- a/drivers/dma/omap-dma.c
> +++ b/drivers/dma/omap-dma.c
> @@ -1288,6 +1288,10 @@ static int omap_dma_slave_config(struct dma_chan *chan, struct dma_slave_config
> cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
> return -EINVAL;
>
> + if (cfg->src_maxburst > chan->device->max_burst ||
> + cfg->dst_maxburst > chan->device->max_burst)
> + return -EINVAL;
> +
> memcpy(&c->cfg, cfg, sizeof(c->cfg));
>
> return 0;
> @@ -1482,6 +1486,7 @@ static int omap_dma_probe(struct platform_device *pdev)
> od->ddev.dst_addr_widths = OMAP_DMA_BUSWIDTHS;
> od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
> od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
> + od->ddev.max_burst = SZ_16M - 1; /* CCEN: 24bit unsigned */
> od->ddev.dev = &pdev->dev;
> INIT_LIST_HEAD(&od->ddev.channels);
> spin_lock_init(&od->lock);
> --
> 2.14.1
>
>
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>
>

--
~Vinod