> > +static int tegra_i2c_init_dma_param(struct tegra_i2c_dev *i2c_dev,
> > + bool dma_to_memory)
> > +{
> > + struct dma_chan *dma_chan;
> > + u32 *dma_buf;
> > + dma_addr_t dma_phys;
> > + int ret;
> > + const char *chan_name = dma_to_memory ? "rx" : "tx";
26.01.2019 3:28, Dmitry Osipenko пишет:
> 24.01.2019 23:51, Sowjanya Komatineni пишет:
>> This patch adds DMA support for Tegra I2C.
>>
>> Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
>> transfer size of the max FIFO depth and DMA mode is used for
>> transfer size higher than
24.01.2019 23:51, Sowjanya Komatineni пишет:
> This patch adds DMA support for Tegra I2C.
>
> Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
> transfer size of the max FIFO depth and DMA mode is used for
> transfer size higher than max FIFO depth to save CPU overhead.
>
> PIO
> > > >>> + if (i2c_dev->has_dma) {
> > > >>> + ret = tegra_i2c_init_dma_param(i2c_dev, true);
> > > >>> + if (ret == -EPROBE_DEFER)
> > > >>> + goto disable_div_clk;
> > > >>> + ret = tegra_i2c_init_dma_param(i2c_dev, false);
> > > >>>
On Fri, Jan 25, 2019 at 09:11:54PM +, Sowjanya Komatineni wrote:
>
>
> > >>> + if (i2c_dev->has_dma) {
> > >>> + ret = tegra_i2c_init_dma_param(i2c_dev, true);
> > >>> + if (ret == -EPROBE_DEFER)
> > >>> + goto disable_div_clk;
> > >>>
24.01.2019 23:51, Sowjanya Komatineni пишет:
> This patch adds DMA support for Tegra I2C.
>
> Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
> transfer size of the max FIFO depth and DMA mode is used for
> transfer size higher than max FIFO depth to save CPU overhead.
>
> PIO
> > + if (i2c_dev->has_dma) {
> > + ret = tegra_i2c_init_dma_param(i2c_dev, true);
> > + if (ret == -EPROBE_DEFER)
> > + goto disable_div_clk;
> > + ret = tegra_i2c_init_dma_param(i2c_dev, false);
> > +
26.01.2019 0:49, Dmitry Osipenko пишет:
> 3) After applying these patches I2C transfers are failing on Tegra20 with
> "tegra-i2c 7000c400.i2c: Failed to allocate the DMA buffer".
>
Actually scratch the above, turned out I haven't applied patches correctly. In
fact patches are failing to
24.01.2019 23:51, Sowjanya Komatineni пишет:
> This patch adds DMA support for Tegra I2C.
>
> Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
> transfer size of the max FIFO depth and DMA mode is used for
> transfer size higher than max FIFO depth to save CPU overhead.
>
> PIO
26.01.2019 0:11, Sowjanya Komatineni пишет:
>
>
> + if (i2c_dev->has_dma) {
> + ret = tegra_i2c_init_dma_param(i2c_dev, true);
> + if (ret == -EPROBE_DEFER)
> + goto disable_div_clk;
> + ret = tegra_i2c_init_dma_param(i2c_dev, false);
> >>> + if (i2c_dev->has_dma) {
> >>> + ret = tegra_i2c_init_dma_param(i2c_dev, true);
> >>> + if (ret == -EPROBE_DEFER)
> >>> + goto disable_div_clk;
> >>> + ret = tegra_i2c_init_dma_param(i2c_dev, false);
> >>> + if (ret == -EPROBE_DEFER)
> >>> +
25.01.2019 23:31, Sowjanya Komatineni пишет:
>
>>> + if (i2c_dev->has_dma) {
>>> + ret = tegra_i2c_init_dma_param(i2c_dev, true);
>>> + if (ret == -EPROBE_DEFER)
>>> + goto disable_div_clk;
>>> + ret = tegra_i2c_init_dma_param(i2c_dev, false);
>>>
> > + if (i2c_dev->has_dma) {
> > + ret = tegra_i2c_init_dma_param(i2c_dev, true);
> > + if (ret == -EPROBE_DEFER)
> > + goto disable_div_clk;
> > + ret = tegra_i2c_init_dma_param(i2c_dev, false);
> > + if (ret == -EPROBE_DEFER)
> > +
24.01.2019 23:51, Sowjanya Komatineni пишет:
> This patch adds DMA support for Tegra I2C.
>
> Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
> transfer size of the max FIFO depth and DMA mode is used for
> transfer size higher than max FIFO depth to save CPU overhead.
>
> PIO
This patch adds DMA support for Tegra I2C.
Tegra I2C TX and RX FIFO depth is 8 words. PIO mode is used for
transfer size of the max FIFO depth and DMA mode is used for
transfer size higher than max FIFO depth to save CPU overhead.
PIO mode needs full intervention of CPU to fill or empty FIFO's
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