Re: [PATCH v3 1/3] dmaengine: qcom: gpi: Add I2C bus recovery opcode support

[Aniket RANDIVE]

On 10/27/2026 7:04 PM, Mukesh Savaliya wrote:
> On 10/27/2026 10:43 AM, Aniket Randive wrote:
> [...]
> > diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c
> > index c41bfac65ddf..394e7287f6e9 100644
> > --- a/drivers/dma/qcom/gpi.c
> > +++ b/drivers/dma/qcom/gpi.c
>
> [...]
>
> > @@ -1692,6 +1709,7 @@ static int gpi_create_i2c_tre(struct gchan 
> > *chan, struct gpi_desc *desc,
> >               tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_BEI);
> >       }
> > +log_tre:
> >       for (i = 0; i < tre_idx; i++)
> >           dev_dbg(dev, "TRE:%d %x:%x:%x:%x\n", i, desc->tre[i].dword[0],
> >               desc->tre[i].dword[1], desc->tre[i].dword[2], desc- 
> > >tre[i].dword[3]);
> > @@ -1825,6 +1843,18 @@ gpi_prep_slave_sg(struct dma_chan *chan, struct 
> > scatterlist *sgl,
> >           nr_tre = 2;
> >       if (direction == DMA_DEV_TO_MEM) /* rx */
> >           nr_tre = 1;
> > +    /*
> > +     * Recovery opcodes do not require DMA data TREs, only CONFIG
> > +     * (for set_config) and GO TREs. Since gpi_prep_slave_sg() is
> > +     * shared with SPI, verify the channel is I2C before accessing
> > +     * the configuration data.
> I think i have mentioned earlier also. gpi_prep_slave_sg() Not only 
> shared with spi but rather say, is a common function for all protocols.> 
> +     */

Currently, the GPI driver has only I2C and SPI clients, so I mentioned 
SPI specifically. However, UART may also use GSI mode in the future. 
I’ll update the comment to state that gpi_prep_slave_sg() is common to 
all protocols.

> > +    if (gchan->protocol == QCOM_GPI_I2C) {
> > +        struct gpi_i2c_config *i2c = gchan->config;
> > +
> > +        if (i2c->op == I2C_BUS_CLEAR || i2c->op == I2C_STOP_ON_BUS)
> > +            nr_tre = set_config ? 2 : 1;
> > +    }
> >       /* calculate # of elements required & available */
> >       nr = gpi_ring_num_elements_avail(ch_ring);
> > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/ 
> > i2c-qcom-geni.c
> [...]