Re: [PATCH 2/2] mmc: sdhci-acpi: Ensure connected devices are powered when probing

[Adrian Hunter <adrian.hunter@intel.com>]

On 19/05/16 16:25, Ulf Hansson wrote:
> From: Adrian Hunter <adrian.hunter@intel.com>
> 
> Some devices connected to the SDHCI controller may have separate enabling
> lines that are controlled through GPIO. These devices need to be powered
> on and enabled before probing. This is to ensure all devices connected can
> be seen by the controller.
> 

I have noticed that stable can get dependent patches the wrong way around
(breaking bisectability) when they are not explicitly defined as dependent.
For that reason, I was going to put the EXPORT of acpi_device_fix_up_power()
into this patch.

I think we need at least to mention in this patch that it is dependent on
the other patch.

Also I have more information here:

Reported-by: Laszlo Fiat <laszlo.fiat@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=112571
Link: http://lkml.kernel.org/r/CA+7w51inLtQSr656bJvOjGG9oQWKYPXH+xxDPJKbeJ=CcrkS9Q@mail.gmail.com


> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Tested-by: Laszlo Fiat <laszlo.fiat@gmail.com>
> Cc: <stable@vger.kernel.org> # 4.5+
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/mmc/host/sdhci-acpi.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
> index b2d70ba..2d1c4870 100644
> --- a/drivers/mmc/host/sdhci-acpi.c
> +++ b/drivers/mmc/host/sdhci-acpi.c
> @@ -378,7 +378,7 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	acpi_handle handle = ACPI_HANDLE(dev);
> -	struct acpi_device *device;
> +	struct acpi_device *device, *child;
>  	struct sdhci_acpi_host *c;
>  	struct sdhci_host *host;
>  	struct resource *iomem;
> @@ -390,6 +390,11 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
>  	if (acpi_bus_get_device(handle, &device))
>  		return -ENODEV;
>  
> +	/* Power on the SDHCI controller and its children */
> +	acpi_device_fix_up_power(device);
> +	list_for_each_entry(child, &device->children, node)
> +		acpi_device_fix_up_power(child);
> +
>  	if (acpi_bus_get_status(device) || !device->status.present)
>  		return -ENODEV;
>  
>