On 8/01/20 11:39 am, Hans de Goede wrote: > Based on a sample of 7 DSDTs from Cherry Trail devices using an AXP288 > PMIC depending on the design one of 2 possible LDOs on the PMIC is used > for the MMC signalling voltage, either DLDO3 or GPIO1LDO (GPIO1 pin in > low noise LDO mode). > > The Lenovo Miix 320-10ICR uses GPIO1LDO in the SHC1 ACPI device's DSM > methods to set 3.3 or 1.8 signalling voltage and this appears to work > as advertised, so presumably the device is actually using GPIO1LDO for > the external microSD signalling voltage. > > But this device has a bug in the _PS0 method of the SHC1 ACPI device, > the DSM remembers the last set signalling voltage and the _PS0 restores > this after a (runtime) suspend-resume cycle, but it "restores" the voltage > on DLDO3 instead of setting it on GPIO1LDO as the DSM method does. DLDO3 > is used for the LCD and setting it to 1.8V causes the LCD to go black. > > This issue can be worked around by setting the SDHCI_QUIRK2_NO_1_8_V > quirk on the sdhci_host so that the DSM never gets used to program the > signalling voltage to 1.8V. Could you instead call the 3.3V DSM at runtime suspend time, then the _PS0 would not "restore" the 1.8V value? That should allow you to use 1.8V UHS-I speed modes with SD cards that support them. > > So far we have mostly been able to avoid using device specific quirks in > the sdhci-acpi code, but given that this issue is specific to this one > model and we certainly do not want to disable 1.8V modes everywhere I > see no other option. > > This commit adds a new mechanism for setting sdhci-acpi specific quirks > and a matching sdhci-acpi.quirks module parameter to make testing quirks / > similar issues on other devices easier. > > The first quirk supported by this mechanism is SDHCI_ACPI_QUIRK_SD_NO_1_8V, > which when set causes any slots with the SDHCI_ACPI_SD_CD flag to get the > SDHCI_QUIRK2_NO_1_8_V quirk set on their sdhci_host. > > This commit also adds a DMI table for specifying default quirks for some > models and adds an entry for the Lenovo Miix 320-10ICR which enables the > SDHCI_QUIRK2_NO_1_8_V by default on this model, fixing the LCD going black > when the external microSD slot is used. > > BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=111294 > BugLink: https://gitlab.freedesktop.org/drm/intel/issues/355 > Reported-by: russianneuromancer <russianneuromancer@xxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > drivers/mmc/host/sdhci-acpi.c | 39 +++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c > index 105e73d4a3b9..9f150c73e958 100644 > --- a/drivers/mmc/host/sdhci-acpi.c > +++ b/drivers/mmc/host/sdhci-acpi.c > @@ -23,6 +23,7 @@ > #include <linux/pm.h> > #include <linux/pm_runtime.h> > #include <linux/delay.h> > +#include <linux/dmi.h> > > #include <linux/mmc/host.h> > #include <linux/mmc/pm.h> > @@ -75,6 +76,14 @@ struct sdhci_acpi_host { > unsigned long private[0] ____cacheline_aligned; > }; > > +enum { > + SDHCI_ACPI_QUIRK_SD_NO_1_8V = BIT(0), > +}; > + > +static int quirks = -1; > +module_param(quirks, int, 0444); > +MODULE_PARM_DESC(quirks, "Override sdhci-acpi specific quirks"); Why is a module parameter needed? > + > static inline void *sdhci_acpi_priv(struct sdhci_acpi_host *c) > { > return (void *)c->private; > @@ -647,6 +656,24 @@ static const struct acpi_device_id sdhci_acpi_ids[] = { > }; > MODULE_DEVICE_TABLE(acpi, sdhci_acpi_ids); > > +static const struct dmi_system_id sdhci_acpi_quirks[] = { > + { > + /* > + * The Lenovo Miix 320-10ICR has a bug in the _PS0 method of > + * the SHC1 ACPI device, this bug causes it to reprogram the > + * wrong LDO (DLDO3) to 1.8V if 1.8V modes are used and the > + * card is (runtime) suspended + resumed. DLDO3 is used for > + * the LCD and setting it to 1.8V causes the LCD to go black. > + */ > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), > + DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo MIIX 320-10ICR"), > + }, > + .driver_data = (void *)SDHCI_ACPI_QUIRK_SD_NO_1_8V, > + }, > + {} /* Terminating entry */ > +}; > + > static const struct sdhci_acpi_slot *sdhci_acpi_get_slot(struct acpi_device *adev) > { > const struct sdhci_acpi_uid_slot *u; > @@ -663,6 +690,7 @@ static int sdhci_acpi_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > const struct sdhci_acpi_slot *slot; > struct acpi_device *device, *child; > + const struct dmi_system_id *id; > struct sdhci_acpi_host *c; > struct sdhci_host *host; > struct resource *iomem; > @@ -670,6 +698,14 @@ static int sdhci_acpi_probe(struct platform_device *pdev) > size_t priv_size; > int err; > > + if (quirks == -1) { > + id = dmi_first_match(sdhci_acpi_quirks); > + if (id) > + quirks = (long)id->driver_data; > + else > + quirks = 0; > + } > + > device = ACPI_COMPANION(dev); > if (!device) > return -ENODEV; > @@ -759,6 +795,9 @@ static int sdhci_acpi_probe(struct platform_device *pdev) > dev_warn(dev, "failed to setup card detect gpio\n"); > c->use_runtime_pm = false; > } > + > + if (quirks & SDHCI_ACPI_QUIRK_SD_NO_1_8V) > + host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; > } > > err = sdhci_setup_host(host); >
