Re: [PATCH v2 4/4] i2c: i2c-qcom-geni: Enable i2c controller sharing between two subsystems

[Mukesh Kumar Savaliya]

Hi Andi, Sorry for late reply on this.

On 9/7/2024 1:26 PM, Andi Shyti wrote:
> Hi Mukesh,
>
> On Sat, Sep 07, 2024 at 12:44:38AM GMT, Mukesh Kumar Savaliya wrote:
> > Add support to share I2C SE by two Subsystems in a mutually exclusive way.
> > Use  "qcom,shared-se" flag in a particular i2c instance node if the
> > usecase requires i2c controller to be shared.
> >
> > I2C driver just need to mark first_msg and last_msg flag to help indicate
> > GPI driver to  take lock and unlock TRE there by protecting from concurrent
> > access from other EE or Subsystem.
> >
> > gpi_create_i2c_tre() function at gpi.c will take care of adding Lock and
> > Unlock TRE for the respective transfer operations.
> >
> > Since the GPIOs are also shared for the i2c bus between two SS, do not
> > touch GPIO configuration during runtime suspend and only turn off the
> > clocks. This will allow other SS to continue to transfer the data
> > without any disturbance over the IO lines.
>
> if I remember correctly, someone already commented on your
> patches to explain and expand the achronyms you are using. Please
> improve the commit log so that people who don't know this device
> can understand.
Sure, Andi. Noted and addressed over comment. Will add full form for the 
acronyms.
> ...
>
> > @@ -631,8 +636,11 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
> >   		dma_async_issue_pending(gi2c->tx_c);
> >   
> >   		time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
> > -		if (!time_left)
> > +		if (!time_left) {
> > +			dev_err(gi2c->se.dev, "I2C timeout gpi flags:%d addr:0x%x\n",
> > +						gi2c->cur->flags, gi2c->cur->addr);
>
> Please, don't print out here. The user doesn't really need to
> know, let the upper levels decide what to do.
Sure, can remove this completely and user can handle , print it.

> >   			gi2c->err = -ETIMEDOUT;
> > +		}
> >   
> >   		if (gi2c->err) {
> >   			ret = gi2c->err;
> > @@ -800,6 +808,11 @@ static int geni_i2c_probe(struct platform_device *pdev)
> >   		gi2c->clk_freq_out = KHZ(100);
> >   	}
> >   
> > +	if (of_property_read_bool(pdev->dev.of_node, "qcom,shared-se")) {
> > +		gi2c->is_shared = true;
> > +		dev_dbg(&pdev->dev, "Shared SE Usecase\n");
>
> Please, improve this debug message.
"I2C is shared between subsystems" ?
> The rest looks good to me.
>
> Thanks,
> Andi