Re: [PATCH 16/16] soc: imx: gpcv2: remove waiting handshake in power up

[Peng Fan (OSS)]

On 2021/4/29 22:34, Lucas Stach wrote:
> Am Donnerstag, dem 29.04.2021 um 15:30 +0800 schrieb Peng Fan (OSS):
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > i.MX8MM has blk ctl module, the handshake can only finish after setting
> > blk ctl. The blk ctl driver will set the bus clk bit and the handshake
> > will finish there. we just add a delay and suppose the handshake will
> > finish after that.
>
> Instead of this patch, just drop patch 05/16 from this series. I think
> we should leave a comment in the code on why we aren't waiting for the
> handshake ack, as this is non-obvious from looking at the driver code.
>
> Basically add a polished version of the commit log from this patch into
> the driver code.

After thinking more, for power down, we need wait handshake. For power 
up, we could ignore handshake, because BLK-CTL setting bus clk en
will auto trigger handshake.

For power down, the bus clk en already set, and we need wait, otherwise
we need add delay there.

So I would only drop the power up waiting and add some comments there.

Thanks,
Peng.

> Regards,
> Lucas
>
> > Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> > ---
> >   drivers/soc/imx/gpcv2.c | 8 --------
> >   1 file changed, 8 deletions(-)
> >
> > diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c
> > index 49dd137f6b94..04564017bfe9 100644
> > --- a/drivers/soc/imx/gpcv2.c
> > +++ b/drivers/soc/imx/gpcv2.c
> > @@ -251,14 +251,6 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
> >   		regmap_update_bits(domain->regmap, GPC_PU_PWRHSK,
> >   				   domain->bits.hskreq, domain->bits.hskreq);
> >   
> >
> >
> >
> > -		ret = regmap_read_poll_timeout(domain->regmap, GPC_PU_PWRHSK,
> > -					       reg_val,
> > -					       (reg_val & domain->bits.hskack),
> > -					       0, USEC_PER_MSEC);
> > -		if (ret) {
> > -			dev_err(domain->dev, "failed to power up ADB400\n");
> > -			goto out_clk_disable;
> > -		}
> >   	}
> >   
> >
> >
> >
> >   	/* Disable reset clocks for all devices in the domain */