dmaengine: omap-dma: Implement protection for invalid max_burst

the device's max_burst to 16777215 (EN is 24bit unsigned value) so
clients can take this into consideration when setting up the transfer.

During slave transfer preparation check if the requested maxburst is valid.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 8c1665c8fe33a76d81682add52985c94a34263a4..f6dd849159d8637cfaa6a5b2debf76ea1bcc477c 100644 (file)
--- 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);