From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shardar Shariff Md Subject: [PATCH v3] dmaengine: tegra-apb: proper default init of channel slave_id Date: Fri, 22 Apr 2016 19:44:39 +0530 Message-ID: <1461334479-27985-1-git-send-email-smohammed@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, gnurou-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org Cc: Shardar Shariff Md List-Id: linux-tegra@vger.kernel.org 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 --- 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