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ACPI: x86: Add PNP_UART1_SKIP quirk for Lenovo Blade2 tablets
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BugLink: https://bugs.launchpad.net/bugs/2075154

[ Upstream commit d8f2038 ]

The x86 Android tablets on which quirks to skip looking for a matching
UartSerialBus resource and instead unconditionally create a serial bus
device (serdev) are necessary there are 2 sorts of serialports:

ACPI enumerated highspeed designware UARTs, these are the ones which
typcially need to be skipped since they need a serdev for the attached
BT HCI.

A PNP enumerated UART which is part of the PCU. So far the existing
quirks have ignored this. But on the Lenovo Yoga Tablet 2 Pro 1380
models this is used for a custom fastcharging protocol. There is
a Micro USB switch which can switch the USB data lines to this uart
and then a 600 baud protocol is used to configure the charger for
a voltage higher then 5V.

Add a new ACPI_QUIRK_PNP_UART1_SKIP quirk type and set this for
the existing entry for the Lenovo Yoga Tablet 2 830 / 1050 models.
Note this will lead to unnecessarily also creating a serdev for
the PCU UART on the 830 / 1050 which don't need this, but the UART
is not used otherwise there so that is not a problem.

Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Manuel Diewald <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>
Signed-off-by: Roxana Nicolescu <[email protected]>
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jwrdegoede authored and roxanan1996 committed Aug 13, 2024
1 parent a94eef5 commit a60b99b
Showing 1 changed file with 13 additions and 7 deletions.
20 changes: 13 additions & 7 deletions drivers/acpi/x86/utils.c
Original file line number Diff line number Diff line change
Expand Up @@ -256,9 +256,10 @@ bool force_storage_d3(void)
#define ACPI_QUIRK_SKIP_I2C_CLIENTS BIT(0)
#define ACPI_QUIRK_UART1_SKIP BIT(1)
#define ACPI_QUIRK_UART1_TTY_UART2_SKIP BIT(2)
#define ACPI_QUIRK_SKIP_ACPI_AC_AND_BATTERY BIT(3)
#define ACPI_QUIRK_USE_ACPI_AC_AND_BATTERY BIT(4)
#define ACPI_QUIRK_SKIP_GPIO_EVENT_HANDLERS BIT(5)
#define ACPI_QUIRK_PNP_UART1_SKIP BIT(3)
#define ACPI_QUIRK_SKIP_ACPI_AC_AND_BATTERY BIT(4)
#define ACPI_QUIRK_USE_ACPI_AC_AND_BATTERY BIT(5)
#define ACPI_QUIRK_SKIP_GPIO_EVENT_HANDLERS BIT(6)

static const struct dmi_system_id acpi_quirk_skip_dmi_ids[] = {
/*
Expand Down Expand Up @@ -338,6 +339,7 @@ static const struct dmi_system_id acpi_quirk_skip_dmi_ids[] = {
DMI_MATCH(DMI_BIOS_VERSION, "BLADE_21"),
},
.driver_data = (void *)(ACPI_QUIRK_SKIP_I2C_CLIENTS |
ACPI_QUIRK_PNP_UART1_SKIP |
ACPI_QUIRK_SKIP_ACPI_AC_AND_BATTERY),
},
{
Expand Down Expand Up @@ -436,14 +438,18 @@ static int acpi_dmi_skip_serdev_enumeration(struct device *controller_parent, bo
if (ret)
return 0;

/* to not match on PNP enumerated debug UARTs */
if (!dev_is_platform(controller_parent))
return 0;

dmi_id = dmi_first_match(acpi_quirk_skip_dmi_ids);
if (dmi_id)
quirks = (unsigned long)dmi_id->driver_data;

if (!dev_is_platform(controller_parent)) {
/* PNP enumerated UARTs */
if ((quirks & ACPI_QUIRK_PNP_UART1_SKIP) && uid == 1)
*skip = true;

return 0;
}

if ((quirks & ACPI_QUIRK_UART1_SKIP) && uid == 1)
*skip = true;

Expand Down

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