Hi Andy,
On 4/10/24 10:06 PM, Andy Shevchenko wrote:
> On Wed, Apr 10, 2024 at 09:16:39PM +0200, Hans de Goede wrote:
>> The card-detect GPIO for the microSD slot on Asus T100TA / T100TAM models
>> stopped working under Linux after commit 6fd03f024828 ("gpiolib: acpi:
>> support bias pull disable").
>>
>> The GPIO in question is connected to a mechanical switch in the slot
>> which shorts the pin to GND when a card is inserted.
>>
>> The GPIO pin correctly gets configured with a 20K pull-up by the BIOS,
>> but there is a bug in the DSDT where the GpioInt for the card-detect is
>> configured with a PullNone setting:
>>
>> GpioInt (Edge, ActiveBoth, SharedAndWake, PullNone, 0x2710,
>> "\\_SB.GPO0", 0x00, ResourceConsumer, ,
>> )
>> { // Pin list
>> 0x0026
>> }
>>
>> Linux now actually honors the PullNone setting and disables the 20K pull-up
>> configured by the BIOS.
>>
>> Add a new DMI_QUIRK_SD_CD_ENABLE_PULL_UP quirk which when set calls
>> mmc_gpiod_set_cd_config() to re-enable the pull-up and set this for
>> the Asus T100TA models to fix this.
>
> ...
>
>> + mmc_gpiod_set_cd_config(host->mmc,
>> + PIN_CONF_PACKED(PIN_CONFIG_BIAS_PULL_UP, 20000));
>
>
> Just noticed, the PIN_CONF_PACKED() is a helper for pinconf-generic.h. It seems
> unusual to use it directly, and AFAIU documentation, it's for static
> initialisations, however it's not explicitly said.
I saw the static vs runtime comment, but I assumed that applies
to the parameters passed to PIN_CONF_PACKED() being determined at
runtime (not the cases here) vs the parameters being static / const.
Regards,
Hans
