On Wed, Mar 26, 2014 at 08:26:27AM +0100, Marek Vasut wrote: > > > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma != > > > NULL) instead of (i2c_imx->use_dma == true) please ? > > > > But there are two judge conditions. But only the "i2c_imx->dma", but also > > whether "i2c_imx_dma_request" success. > > > > "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL && > > !i2c_imx_dma_request()" > > + /* Init DMA config if support*/ > + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma), > + GFP_KERNEL); > + if (!i2c_imx->dma) { > + dev_info(&pdev->dev, > + "can't allocate dma struct faild use dma.\n"); > + i2c_imx->use_dma = false; > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) { > + dev_info(&pdev->dev, > + "can't request dma chan, faild use dma.\n"); > + i2c_imx->use_dma = false; > + } else { > + i2c_imx->use_dma = true; > + } > > OK, looking at this one more time, why don't you wrap the allocation of i2c_imx- > >dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local > variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at > the end of the i2c_imx_dma_request() function , at the point where you are sure > nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to > check if the DMA is available, no ? > > Shawn, Wolfram, am I talking nonsense or am I just not connecting ? I'm with you, Marek. Shawn -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html