Re: [PATCH] mmc: sdhci-acpi: Only powered up enabled acpi child devices

Adrian Hunter
2017-01-12T10:56:19Z

On 12/01/17 12:03, Ulf Hansson wrote:
> On 21 December 2016 at 00:19, Hans de Goede <hdegoede@redhat.com> wrote:
>> Commit e5bbf30733f9 ("mmc: sdhci-acpi: Ensure connected devices are
>> powered when probing") introduced code to powerup any acpi child
>> nodes listed in the dstd. But some dstd-s list all possible devices
>> used on some board variants, while reporting if the device is actually
>> present and enabled in the status field of the device.
>>
>> So we end up calling the acpi _PS0 (power-on) method for devices which
>> are not actually present. This does not always end well, e.g. on my
>> cube iwork8 air tablet, this results in freezing the entire tablet as
>> soon as the r8723bs module is loaded.
>>
>> This commit fixes this by checking the child device's status.present
>> and status.enabled bits and only call acpi_device_fix_up_power()
>> if both are set.
>>
>> Fixes: e5bbf30733f9 ("mmc: sdhci-acpi: Ensure connected devices are powered when probing")
>> BugLink: https://github.com/hadess/rtl8723bs/issues/80
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>
> Seems like I should add stable tag to this as well!?

Yes I think so.

>
>> ---
>> drivers/mmc/host/sdhci-acpi.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
>> index 92096db..34ee237 100644
>> --- a/drivers/mmc/host/sdhci-acpi.c
>> +++ b/drivers/mmc/host/sdhci-acpi.c
>> @@ -396,7 +396,8 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
>> /* 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 (child->status.present && child->status.enabled)
>> + acpi_device_fix_up_power(child);
>>
>> if (acpi_bus_get_status(device) || !device->status.present)
>> return -ENODEV;
>> --
>> 2.9.3
>>
>
> Adrian, are you happy with this fix?

Yes.

Acked-by: Adrian Hunter <adrian.hunter@intel.com>