On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote: > On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote: > > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote: > > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote: > > > > > > [...] > > > > > > > > > + 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; > > > > > > + } > > > > > > > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL > > > > > > pointer ? > > > > > > > > Then you won't need a separate variable, for this purpose ... > right ? > > > > > > > > Sorry and I think what I know is just to check whether it is NULL. > > > > Then for the second question, maybe there are some other ways, But > > > > I think it is more tidy and easier understanding for using a > > > > separate variable, for this purpose. > > > > > > You are just wasting space and duplicating data, unless I am wrong. > > > > Well, Do you have a better idea? Although I think it's necessary. > > 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()" ��.n��������+%������w��{.n�����{��-��)��jg��������ݢj����G�������j:+v���w�m������w�������h�����٥