Marek Vasut wrote: > On Wednesday, July 23, 2014 at 02:15:02 PM, Lothar Waßmann wrote: > > Hi, > > > > Varka Bhadram wrote: > > > On 07/23/2014 04:41 PM, Yao Yuan wrote: > > > > Hi, > > > > > > > > Thanks for your review. > > > > > > > > Lothar Waßmann wrote: > > > >> Yuan Yao wrote: > > > >>> Add dma support for i2c. This function depend on DMA driver. > > > >>> You can turn on it by write both the dmas and dma-name > > > >>> properties in dts node. > > > >>> > > > >>> Signed-off-by: Yuan Yao <yao.yuan@xxxxxxxxxxxxx> > > > >>> --- > > > >>> > > > >>> drivers/i2c/busses/i2c-imx.c | 377 > > > > > > > > [...] > > > > > > > >>> + > > > >>> +fail_rx: > > > >>> + dma_release_channel(dma->chan_rx); > > > >>> +fail_tx: > > > >>> + dma_release_channel(dma->chan_tx); > > > >>> +fail_al: > > > >>> + devm_kfree(dev, dma); > > > >> > > > >> No need for this one (that's the whole point of using devm_kzalloc())! > > > > > > > > When DMA request failed, I2C will switch to PIO mode. So if the > > > > failed reason is just like DMA channel request failed. At this > > > > time the DMA should free by devm_kfree(). Is it? > > > > > > If probe failed the memory will be freed automatically because we > > > are using devm_kzalloc()... > > > > > > If we use devm_kzalloc() ,no need to free manually on fail... > > > > Yes, but as Yuan Yao stated, the driver will still work without DMA > > but carry around the unecessary allocated imx_i2c_dma struct. > > The devm_kfree() is not in the failure path of the driver's probe() > > function, but in the function that tries to initialize the optional > > DMA support. > > If the DMA fails, I'd just make the entire probe fail. In case you cannot probe > DMA for your hardware, which is exected to be DMA capable, it means > something is wrong anyway. Yes, but if there is something wrong in dma, I think the i2c is innocent. So I think the error message is necessary but i2c can continue work. Best regards, Yuan Yao -- 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
