Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <aa1f187c-786e-16ca-c156-448108f8fcc5@gmail.com>
Date:   Thu, 16 Jun 2022 15:49:03 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.10.0
Subject: Re: [PATCH] soc: mediatek: Introduce mediatek-regulator-coupler
 driver
Content-Language: en-US
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>, matthias.bgg@gmail.com
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, wenst@chromium.org,
        alyssa.rosenzweig@collabora.com, nfraprado@collabora.com
References: <20220616094502.15318-1-angelogioacchino.delregno@collabora.com>
From:   Dmitry Osipenko <digetx@gmail.com>
In-Reply-To: <20220616094502.15318-1-angelogioacchino.delregno@collabora.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

16.06.2022 12:45, AngeloGioacchino Del Regno пишет:
> +static int mediatek_regulator_attach(struct regulator_coupler *coupler,
> +				     struct regulator_dev *rdev)
> +{
> +	struct mediatek_regulator_coupler *mrc = to_mediatek_coupler(coupler);
> +	const char *rdev_name = rdev_get_name(rdev);
> +
> +	if (strstr(rdev_name, "sram")) {
> +		if (mrc->vsram_rdev)
> +			return -EINVAL;
> +		mrc->vsram_rdev = rdev;
> +	}

You should filter out regulators unrelated to SRAM and GPU, see
regulator_find_coupler().

> +	return 0;
> +}
> +
> +static int mediatek_regulator_detach(struct regulator_coupler *coupler,
> +				     struct regulator_dev *rdev)
> +{
> +	struct mediatek_regulator_coupler *mrc = to_mediatek_coupler(coupler);
> +
> +	if (rdev == mrc->vsram_rdev) {
> +		mrc->vsram_rdev = NULL;
> +		return 0;
> +	}

The regulator core should emit error message about GPU regulator failed
to detach because you're returning -EINVAL for it.

> +	return -EINVAL;
> +}