Re: [V2] i2c: i2c-qcom-geni: Correct I2C TRE sequence

[Bryan O'Donoghue]

On 29/01/2024 23:24, Andi Shyti wrote:
> Hi Viken,
>
> as Bryan has done some comments in version 1, please, Cc him to
> this patch.
>
> On Mon, Jan 29, 2024 at 11:40:03AM +0530, Viken Dadhaniya wrote:
> > For i2c read operation, we are getting gsi mode timeout due
> > to malformed TRE(Transfer Ring Element). Currently we are
> > configuring incorrect TRE sequence in gpi driver
> > (drivers/dma/qcom/gpi.c) as below
> >
> > - Sets up CONFIG
> > - Sets up DMA tre
> > - Sets up GO tre
> >
> > As per HPG(Hardware programming guide), We should configure TREs in below
> > sequence for any i2c transfer
> >
> > - Sets up CONFIG tre
> > - Sets up GO tre
> > - Sets up DMA tre
> >
> > For only write operation or write followed by read operation,
> > existing software sequence is correct.
> >
> > for only read operation, TRE sequence need to be corrected.
> > Hence, we have changed the sequence to submit GO tre before DMA tre.
> >
> > Tested covering i2c read/write transfer on QCM6490 RB3 board.
> >
> > Signed-off-by: Viken Dadhaniya <quic_vdadhani@xxxxxxxxxxx>
> > Fixes: commit d8703554f4de ("i2c: qcom-geni: Add support for GPI DMA")
>
> The format is:
>
> Fixes: d8703554f4de ("i2c: qcom-geni: Add support for GPI DMA")
>
> and goes above the SoB.
>
> > ---
> > v1 -> v2:
> > - Remove redundant check.
> > - update commit log.
> > - add fix tag.
> > ---
> > ---
> >   drivers/i2c/busses/i2c-qcom-geni.c | 14 +++++++-------
> >   1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> > index 0d2e7171e3a6..da94df466e83 100644
> > --- a/drivers/i2c/busses/i2c-qcom-geni.c
> > +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> > @@ -613,20 +613,20 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
> >   
> >   		peripheral.addr = msgs[i].addr;
> >   
> > +		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
> > +				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
> > +		if (ret)
> > +			goto err;
> > +
> >   		if (msgs[i].flags & I2C_M_RD) {
> >   			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
> >   					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
> >   			if (ret)
> >   				goto err;
> > -		}
> > -
> > -		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
> > -				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
> > -		if (ret)
> > -			goto err;
> >   
> > -		if (msgs[i].flags & I2C_M_RD)
> >   			dma_async_issue_pending(gi2c->rx_c);
> > +		}
> > +
>
> Bryan, could you please check here?
>
> Thanks for your review!
>
> Andi

Assuming the Fixes tag is fixed.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx> # qrb5165-rb5

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