linux-kernel - Re: [PATCH] pinctrl: freescale: avoid overwriting pin config when freeing GPIO

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Date:   Thu, 29 Sep 2016 12:16:05 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Vladimir Zapolskiy <vladimir_zapolskiy@...tor.com>
Cc:     Stefan Agner <stefan@...er.ch>, linus.walleij@...aro.org,
        shawnguo@...nel.org, aalonso@...escale.com, b38343@...escale.com,
        ldewangan@...dia.com, van.freenix@...il.com,
        p.zabel@...gutronix.de, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] pinctrl: freescale: avoid overwriting pin config when
 freeing GPIO

On 28-09-16, 15:07, Vladimir Zapolskiy wrote:
> I would expect that the change below improves the situation, but I didn't
> perform any tests and here the core change is governed by the accepted
> i.MX i2c bus driver specific changes, thus conceptually it may be incorrect:
> 
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index da3a02ef4a31..3a4f59c3c3e6 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -697,9 +697,6 @@ static int i2c_generic_recovery(struct i2c_adapter *adap)
>  	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
>  	int i = 0, val = 1, ret = 0;
> -	if (bri->prepare_recovery)
> -		bri->prepare_recovery(adap);
> -
>  	bri->set_scl(adap, val);
>  	ndelay(RECOVERY_NDELAY);
> @@ -725,22 +722,34 @@ static int i2c_generic_recovery(struct i2c_adapter *adap)
>  		ndelay(RECOVERY_NDELAY);
>  	}
> -	if (bri->unprepare_recovery)
> -		bri->unprepare_recovery(adap);
> -
>  	return ret;
>  }
>  int i2c_generic_scl_recovery(struct i2c_adapter *adap)
>  {
> -	return i2c_generic_recovery(adap);
> +	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
> +	int ret;
> +
> +	if (bri->prepare_recovery)
> +		bri->prepare_recovery(adap);
> +
> +	ret = i2c_generic_recovery(adap);
> +
> +	if (bri->unprepare_recovery)
> +		bri->unprepare_recovery(adap);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
>  int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
>  {
> +	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
>  	int ret;
> +	if (bri->prepare_recovery)
> +		bri->prepare_recovery(adap);
> +
>  	ret = i2c_get_gpios_for_recovery(adap);
>  	if (ret)
>  		return ret;
> @@ -748,6 +757,9 @@ int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
>  	ret = i2c_generic_recovery(adap);
>  	i2c_put_gpios_for_recovery(adap);
> +	if (bri->unprepare_recovery)
> +		bri->unprepare_recovery(adap);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);

That looks to like a hack made just to make things work on one platform.

I would rather wait for an answer to my query first, which I asked in a separate
email.
 
-- 
viresh