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

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 11-Nov-24 11:56 AM, Adrian Hunter wrote:
> 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;
> 
> };

I see, will do for v3.

>> 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.

Ok, I'll add the kmemdump helper for v3.

Regards,

Hans