Re: [PATCH v17 2/4] dmaengine: tegra: Add tegra gpcdma driver

Dmitry Osipenko
2022-01-30T10:13:59Z

30.01.2022 13:08, Dmitry Osipenko пишет:
> 30.01.2022 13:05, Dmitry Osipenko пишет:
>> static int tegra_dma_device_resume(struct dma_chan *dc)
>> {
>> struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
>> u32 val;
>>
>> if (!tdc->tdma->chip_data->hw_support_pause)
>> return -ENOSYS;
>>
>> if (!tdc->dma_desc)
>> return 0;
>>
>> val = tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSRE);
>> val &= ~TEGRA_GPCDMA_CHAN_CSRE_PAUSE;
>> tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSRE, val);
>>
>> enable_irq(tdc->irq);
>
> Correction:
>
> if (tdc->dma_desc) {
> val = tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSRE);
> val &= ~TEGRA_GPCDMA_CHAN_CSRE_PAUSE;
> tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSRE, val);
> }
>
> enable_irq(tdc->irq);

And apparently, tegra_dma_terminate_all() also needs to take care of
removing the PAUSE bit. Otherwise it won't be possible to unpause
channel after the termination.