Re: [PATCH v2] mmc: sdhci-pci: Add DMI quirk for missing CD GPIO on Vexia Edu Atla 10 tablet

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

On 7/11/24 12:00, Hans de Goede wrote:
> The Vexia Edu Atla 10 tablet distributed to schools in the Spanish
> Andalucía region has no ACPI fwnode associated with the SDHCI controller
> for its microsd-slot and thus has no ACPI GPIO resource info.
> 
> This causes the following error to be logged and the slot to not work:
> [   10.572113] sdhci-pci 0000:00:12.0: failed to setup card detect gpio
> 
> Add a DMI quirk table for providing gpiod_lookup_tables with manually
> provided CD GPIO info and use this DMI table to provide the CD GPIO info
> on this tablet. This fixes the microsd-slot not working.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> - Make sdhci_pci_dmi_cd_gpio_overrides static const instead of just const
> - Drop duplicate #include <linux/dmi.h> (already there at the end)
> ---
>  drivers/mmc/host/sdhci-pci-core.c | 38 +++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index ed45ed0bdafd..9c2bce5e88d9 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -21,6 +21,7 @@
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
>  #include <linux/gpio.h>
> +#include <linux/gpio/machine.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/pm_qos.h>
>  #include <linux/debugfs.h>
> @@ -2054,6 +2055,29 @@ static const struct dev_pm_ops sdhci_pci_pm_ops = {
>   *                                                                           *
>  \*****************************************************************************/
>  
> +/* DMI quirks for devices with missing or broken CD GPIO info */
> +static struct gpiod_lookup_table vexia_edu_atla10_cd_gpios = {
> +	.dev_id = "0000:00:12.0",
> +	.table = {
> +		GPIO_LOOKUP("INT33FC:00", 38, "cd", GPIO_ACTIVE_HIGH),
> +		{ }
> +	},
> +};
> +
> +static const struct dmi_system_id sdhci_pci_dmi_cd_gpio_overrides[] = {
> +	{
> +		/* Vexia Edu Atla 10 tablet 9V version */
> +		.matches = {
> +			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
> +			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
> +			/* Above strings are too generic, also match on BIOS date */
> +			DMI_MATCH(DMI_BIOS_DATE, "08/25/2014"),
> +		},
> +		.driver_data = (void *)&vexia_edu_atla10_cd_gpios,
> +	},
> +	{ }
> +};

Can this be in struct sdhci_pci_fixes?

> +
>  static struct sdhci_pci_slot *sdhci_pci_probe_slot(
>  	struct pci_dev *pdev, struct sdhci_pci_chip *chip, int first_bar,
>  	int slotno)
> @@ -2129,8 +2153,22 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
>  		device_init_wakeup(&pdev->dev, true);
>  
>  	if (slot->cd_idx >= 0) {
> +		struct gpiod_lookup_table *cd_gpio_lookup_table = NULL;
> +		const struct dmi_system_id *dmi_id;
> +
> +		dmi_id = dmi_first_match(sdhci_pci_dmi_cd_gpio_overrides);
> +		if (dmi_id)
> +			cd_gpio_lookup_table = dmi_id->driver_data;
> +
> +		if (cd_gpio_lookup_table)
> +			gpiod_add_lookup_table(cd_gpio_lookup_table);

If we were probing asynchronously, gpiod_add_lookup_table() and
gpiod_remove_lookup_table() could race.

I'd suggest making vexia_edu_atla10_cd_gpios const and kmemdup'ing
and freeing it.

Add helper functions something like:

		cd_gpio_lookup_table = sdhci_pci_add_gpio_lookup_table(chip);
		if (IS_ERR(cd_gpio_lookup_table)) {
			etc
		}

		...

		sdhci_pci_remove_gpio_lookup_table(cd_gpio_lookup_table);

> +
>  		ret = mmc_gpiod_request_cd(host->mmc, "cd", slot->cd_idx,
>  					   slot->cd_override_level, 0);
> +
> +		if (cd_gpio_lookup_table)
> +			gpiod_remove_lookup_table(cd_gpio_lookup_table);
> +
>  		if (ret && ret != -EPROBE_DEFER)
>  			ret = mmc_gpiod_request_cd(host->mmc, NULL,
>  						   slot->cd_idx,