01.02.2019 22:20, Sowjanya Komatineni пишет:
>
>>> +static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev) {
>>> + struct dma_chan *dma_chan;
>>> + u32 *dma_buf;
>>> + dma_addr_t dma_phys;
>>> + int err = 0;
>>> +
>>> + if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA))
>>> + return -ENODEV;
>>
>> Driver shall not fail to probe if DMA driver is disabled, but to continue with the PIO-only mode available.
>>
>> Should be:
>>
>> if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA))
>> return 0;
>>
> Except EPROBE_DEFER, anything else returned from tegra_i2c_init_dma (ENODEV/ENOMEM) is ignored in i2c_probe
> DMA mode decision is based on xfer size and availability of dma channel or can be changed based on valid dma buf to shorten the line.
>
Ah, sorry. I missed that, seems good then.
