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 11/11/24 12:26, Hans de Goede wrote:
> Hi Adrian,
> 
> Thank you for the review.
> 
> On 11-Nov-24 11:07 AM, Adrian Hunter wrote:
>> 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?
> 
> You mean at a "struct gpiod_lookup_table *cd_gpio_lookup_table" member
> to struct sdhci_pci_fixes and then set that for this tablet from say
> byt_sd_probe_slot() based on the DMI match (1) ?

I was thinking of adding sdhci_pci_dmi_cd_gpio_overrides to
sdhci_pci_fixes and the whole lot can be const.  Can also add the same
overrides to multiple sdhci_pci_fixes instances because it is just
a pointer.

struct sdhci_pci_fixes {

	const struct dmi_system_id *dmi_cd_gpio_overrides;

};

> 
> Before you ask I just checked and the PCI subsystem ids are generic
> (which matches how broken the firmware is on this device in general).
> 
> I did consider that, but that would require un-constifying 
> "struct sdhci_pci_fixes sdhci_intel_byt_sd" so that byt_sd_probe_slot()
> can modify it.
> 
> I went with the current approach to be able to keep that struct const.
> With your async probing argument from below I think making
> byt_sd_probe_slot() set cd_gpio_lookup_table in sdhci_pci_fixes
> is a good idea, even if it does require removing the const from
> "struct sdhci_pci_fixes sdhci_intel_byt_sd".
> 
> 1) Before you ask I just checked and the PCI subsystem ids are generic,
> which matches how broken the firmware is on this device in general.
> 
> 
>>> +
>>>  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.
> 
> That is a good point.
> 
>> 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,
>>
> 
> That should work yes, I do wonder after adding cd_gpio_lookup_table to
> sdhci_pci_fixes only 1 controller will have it set (only the one for
> the external slot, not the SDIO wifi and eMMC controllers).
> So I think that this race goes away then, avoiding the need to kmemdup ?

Practically speaking, I guess, but I would prefer things to be correct
no matter what/how hardware presents itself.

> 
> Note I'm fine with proceeding either way, just wondering if we cannot
> keep things a bit more simple after adding cd_gpio_lookup_table to
> sdhci_pci_fixes ?

Shouldn't be too bad.  Instead of sdhci_pci_dmi_cd_gpio_overrides being
global it would be chip->fixes->dmi_cd_gpio_overrides, and add kmemdup
and an error path for it.

> 
> Regards,
> 
> Hans
> 
>