diff options
| author | Mika Westerberg <mika.westerberg@linux.intel.com> | 2018-08-30 11:50:13 +0300 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2018-08-30 22:53:44 +0200 |
| commit | 7fd6d98b89f382d414e1db528e29a67bbd749457 (patch) | |
| tree | b2661725294f667f216e6b45a19175a2572a42b6 /drivers | |
| parent | 5b394b2ddf0347bef56e50c69a58773c94343ff3 (diff) | |
i2c: i801: Allow ACPI AML access I/O ports not reserved for SMBus
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.
Fixes: 7ae81952cda ("i2c: i801: Allow ACPI SystemIO OpRegion to conflict with PCI BAR")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200737
Reported-by: Yussuf Khalil <dev@pp3345.net>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 941c223f6491..04b60a349d7e 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -1415,6 +1415,13 @@ static void i801_add_tco(struct i801_priv *priv) } #ifdef CONFIG_ACPI +static bool i801_acpi_is_smbus_ioport(const struct i801_priv *priv, + acpi_physical_address address) +{ + return address >= priv->smba && + address <= pci_resource_end(priv->pci_dev, SMBBAR); +} + static acpi_status i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits, u64 *value, void *handler_context, void *region_context) @@ -1430,7 +1437,7 @@ i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits, */ mutex_lock(&priv->acpi_lock); - if (!priv->acpi_reserved) { + if (!priv->acpi_reserved && i801_acpi_is_smbus_ioport(priv, address)) { priv->acpi_reserved = true; dev_warn(&pdev->dev, "BIOS is accessing SMBus registers\n"); |