linux-kernel - Re: [PATCH 2/3] mmc: sdhci-acpi: Check device status before calling fix_up

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Date:   Sat, 25 Feb 2017 19:31:49 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Adrian Hunter <adrian.hunter@...el.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Jean Delvare <jdelvare@...e.com>
Cc:     Takashi Iwai <tiwai@...e.de>,
        "russianneuromancer @ ya . ru" <russianneuromancer@...ru>,
        linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] mmc: sdhci-acpi: Check device status before calling
 fix_up_power()

HI,

On 25-02-17 18:23, Hans de Goede wrote:
> Calling acpi_device_fix_up_power() on a device which is not present
> is not a good idea.
>
> While at it also call acpi_bus_get_status() on the children before
> the status check to make sure that child->status contains valid data.

This paragraph of the commit msg should be removed, I dropped
that part of the patch since acpi_init_device_object() already sets
status and all acpi_device's get that called upon creation.

Regards,

Hans



>
> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> ---
>  drivers/mmc/host/sdhci-acpi.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
> index 96465ff..873beae 100644
> --- a/drivers/mmc/host/sdhci-acpi.c
> +++ b/drivers/mmc/host/sdhci-acpi.c
> @@ -394,15 +394,15 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
>  	if (acpi_bus_get_device(handle, &device))
>  		return -ENODEV;
>
> +	if (acpi_bus_get_status(device) || !device->status.present)
> +		return -ENODEV;
> +
>  	/* Power on the SDHCI controller and its children */
>  	acpi_device_fix_up_power(device);
>  	list_for_each_entry(child, &device->children, node)
>  		if (child->status.present && child->status.enabled)
>  			acpi_device_fix_up_power(child);
>
> -	if (acpi_bus_get_status(device) || !device->status.present)
> -		return -ENODEV;
> -
>  	if (sdhci_acpi_byt_defer(dev))
>  		return -EPROBE_DEFER;
>
>