Re: [PATCH v8 1/4] i2c: tegra: Do not configure DMA if not supported

[Kartik Rajput]

On 17/09/25 19:38, Jon Hunter wrote:
> On 17/09/2025 09:56, Kartik Rajput wrote:
> > On Tegra264, not all I2C controllers have the necessary interface to
> > GPC DMA, this causes failures when function tegra_i2c_init_dma()
> > is called.
> >
> > Ensure that "dmas" device-tree property is present before initializing
> > DMA in function tegra_i2c_init_dma().
> >
> > Signed-off-by: Kartik Rajput <kkartik@xxxxxxxxxx>
> > ---
> > v2 -> v4:
> >     * Add debug print if DMA is not supported by the I2C controller.
> > v1 -> v2:
> >     * Update commit message to clarify that some I2C controllers may
> >       not have the necessary interface to GPC DMA.
> > ---
> >   drivers/i2c/busses/i2c-tegra.c | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> > index e533460bccc3..d908e5e3f0af 100644
> > --- a/drivers/i2c/busses/i2c-tegra.c
> > +++ b/drivers/i2c/busses/i2c-tegra.c
> > @@ -446,6 +446,11 @@ static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
> >       u32 *dma_buf;
> >       int err;
> > +    if (!of_property_present(i2c_dev->dev->of_node, "dmas")) {
> > +        dev_dbg(i2c_dev->dev, "DMA not available, falling back to PIO\n");
> > +        return 0;
> > +    }
> > +
> >       if (IS_VI(i2c_dev))
> >           return 0;
>
> No issue with this change, but we have a few checks for DMA support in this function and so it would be nice to have them altogether.
>
> Jon

Ack.

Thanks,
Kartik