Initialize default channel slave_id(req_sel) to invalid id (i.e max supported slave id + 1) to avoid overwriting of slave_id during tegra_dma_slave_config() with client data if slave_id is not initialized through DT
Signed-off-by: Shardar Shariff Md <[email protected]> --- Changes from v1: - Instead of initializing the slave id to -1 define macros for max slave id and invalid slave id and do the checks accordingly. Changes from v2: - Check slave id boundary before dma channel is allocated to avoid channel leakage. --- drivers/dma/tegra20-apb-dma.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index 3871f29..f57cee85 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -54,6 +54,7 @@ #define TEGRA_APBDMA_CSR_ONCE BIT(27) #define TEGRA_APBDMA_CSR_FLOW BIT(21) #define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT 16 +#define TEGRA_APBDMA_CSR_REQ_SEL_MASK 0x1F #define TEGRA_APBDMA_CSR_WCOUNT_MASK 0xFFFC /* STATUS register */ @@ -114,6 +115,9 @@ /* Channel base address offset from APBDMA base address */ #define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET 0x1000 +#define TEGRA_APBDMA_SLAVE_ID_MAX TEGRA_APBDMA_CSR_REQ_SEL_MASK +#define TEGRA_APBDMA_SLAVE_ID_INVALID (TEGRA_APBDMA_SLAVE_ID_MAX + 1) + struct tegra_dma; /* @@ -353,7 +357,7 @@ static int tegra_dma_slave_config(struct dma_chan *dc, } memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig)); - if (!tdc->slave_id) + if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID) tdc->slave_id = sconfig->slave_id; tdc->config_init = true; return 0; @@ -1236,7 +1240,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc) } pm_runtime_put(tdma->dev); - tdc->slave_id = 0; + tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID; } static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec, @@ -1245,13 +1249,20 @@ static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec, struct tegra_dma *tdma = ofdma->of_dma_data; struct dma_chan *chan; struct tegra_dma_channel *tdc; + unsigned int slave_id; + + slave_id = dma_spec->args[0]; + if (slave_id > TEGRA_APBDMA_SLAVE_ID_MAX) { + dev_err(tdma->dev, "Invalid slave id: %d\n", slave_id); + return NULL; + } chan = dma_get_any_slave_channel(&tdma->dma_dev); if (!chan) return NULL; tdc = to_tegra_dma_chan(chan); - tdc->slave_id = dma_spec->args[0]; + tdc->slave_id = slave_id; return chan; } @@ -1389,6 +1400,7 @@ static int tegra_dma_probe(struct platform_device *pdev) &tdma->dma_dev.channels); tdc->tdma = tdma; tdc->id = i; + tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID; tasklet_init(&tdc->tasklet, tegra_dma_tasklet, (unsigned long)tdc); -- 1.8.1.5
