| Message ID | 20180830085013.64021-1-mika.westerberg@linux.intel.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] i2c: i801: Allow ACPI AML access I/O ports not reserved for SMBus | expand |
On Thu, Aug 30, 2018 at 11:50:13AM +0300, Mika Westerberg wrote: > 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> Applied to for-current, thanks!
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");
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> --- Changes from v1: - Correct off-by-one in the address check - Added Jean's tag drivers/i2c/busses/i2c-i801.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)