Commit 7ae81952cda ("i2c: i801: Allow ACPI SystemIO OpRegion to conflict with PCI BAR") made it possible for AML code to access SMBus I/O ports by installing custom SystemIO OpRegion handler and blocking i80i driver access upon first AML read/write to this OpRegion. However, while ThinkPad T560 does have SystemIO OpRegion declared under the SMBus device, it does not access any of the SMBus registers: Device (SMBU) { ... OperationRegion (SMBP, PCI_Config, 0x50, 0x04) Field (SMBP, DWordAcc, NoLock, Preserve) { , 5, TCOB, 11, Offset (0x04) } Name (TCBV, 0x00) Method (TCBS, 0, NotSerialized) { If ((TCBV == 0x00)) { TCBV = (\_SB.PCI0.SMBU.TCOB << 0x05) } Return (TCBV) /* \_SB_.PCI0.SMBU.TCBV */ } OperationRegion (TCBA, SystemIO, TCBS (), 0x10) Field (TCBA, ByteAcc, NoLock, Preserve) { Offset (0x04), , 9, CPSC, 1 } } Problem with the current approach is that it blocks all I/O port access and because this system has touchpad connected to the SMBus controller after first AML access (happens during suspend/resume cycle) the touchpad fails to work anymore. Fix this so that we allow ACPI AML I/O port access if it does not touch the region reserved for the SMBus.
Unified · Split
| @@ -1415,6 +1415,13 @@ static void i801_add_tco(struct i801_priv *priv) · 1414 unmodified lines | ||
| 1415 | 1415 | } |
| 1416 | 1416 | |
| 1417 | 1417 | #ifdef CONFIG_ACPI |
| 1418 | +static bool i801_acpi_is_smbus_ioport(const struct i801_priv *priv, | |
| 1419 | + acpi_physical_address address) | |
| 1420 | +{ | |
| 1421 | + return address >= priv->smba && | |
| 1422 | + address <= pci_resource_end(priv->pci_dev, SMBBAR); | |
| 1423 | +} | |
| 1424 | + | |
| 1418 | 1425 | static acpi_status |
| 1419 | 1426 | i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits, |
| 1420 | 1427 | u64 *value, void *handler_context, void *region_context) |
| @@ -1430,7 +1437,7 @@ i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits, · 9 unmodified lines | ||
| 1430 | 1437 | */ |
| 1431 | 1438 | mutex_lock(&priv->acpi_lock); |
| 1432 | 1439 | |
| 1433 | − if (!priv->acpi_reserved) { | |
| 1440 | + if (!priv->acpi_reserved && i801_acpi_is_smbus_ioport(priv, address)) { | |
| 1434 | 1441 | priv->acpi_reserved = true; |
| 1435 | 1442 | |
| 1436 | 1443 | dev_warn(&pdev->dev, "BIOS is accessing SMBus registers\n"); |