Messages in this thread Patch in this message | | | From | Nicolai Stange <> | Subject | Re: [PATCH] i2c / ACPI: Do not touch an I2C device if it belongs to another adapter | Date | Tue, 20 Sep 2016 12:32:11 +0200 |
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Your patch fixes my issue, so feel free to add a
Tested-by: Nicolai Stange <nicstange@gmail.com>
for this either.
But please see my remark below.
Mika Westerberg <mika.westerberg@linux.intel.com> writes:
> When enumerating I2C devices connected to an I2C adapter we scan the whole > namespace (as it is possible to have devices anywhere in that namespace, > not just below the I2C adapter device) and add each found device to the I2C > bus in question. > > Now after commit 525e6fabeae2 ("i2c / ACPI: add support for ACPI > reconfigure notifications") checking of the adapter handle to the one found > in the I2cSerialBus() resource was moved to happen after resources of the > I2C device has been parsed. This means that if the I2cSerialBus() resource > points to an adapter that does not exists in the system we still parse > those resources. This is problematic in particular because > acpi_dev_resource_interrupt() tries to configure GSI if the device also has > an Interrupt() resource. Failing to do that results errrors like this to be > printed on the console: > > [ 10.409490] ERROR: Unable to locate IOAPIC for GSI 37 > > To fix this we pass the I2C adapter to i2c_acpi_get_info() and make sure > the handle matches the one in the I2cSerialBus() resource before doing > anything else to the device. > > Reported-by: Nicolai Stange <nicstange@gmail.com> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > --- > drivers/i2c/i2c-core.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index c61c961cf8f9..eb32cb783fc8 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -168,6 +168,7 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev, > > static int i2c_acpi_get_info(struct acpi_device *adev, > struct i2c_board_info *info, > + struct i2c_adapter *adapter, > acpi_handle *adapter_handle) > { > struct list_head resource_list; > @@ -182,6 +183,10 @@ static int i2c_acpi_get_info(struct acpi_device *adev, > if (ret) > return ret; > > + /* The adapter must match the one in I2cSerialBus() connector */ > + if (adapter && ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle) > + return -ENODEV; > +
Would it be sensible to add the adapter presence check you provided earlier, i.e.
+ else if (!adapter) { + /* The adapter must be present */ + if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev)) + return -ENODEV; + if (acpi_bus_get_status(adapter_adev) || !adapter_adev->status.present) + return -ENODEV; + + }
here, because we can't know if ...
> info->fwnode = acpi_fwnode_handle(adev); > *adapter_handle = lookup.adapter_handle; > > @@ -231,10 +236,7 @@ static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level, > if (acpi_bus_get_device(handle, &adev)) > return AE_OK; > > - if (i2c_acpi_get_info(adev, &info, &adapter_handle)) > - return AE_OK; > - > - if (adapter_handle != ACPI_HANDLE(&adapter->dev)) > + if (i2c_acpi_get_info(adev, &info, adapter, &adapter_handle)) > return AE_OK; > > i2c_acpi_register_device(adapter, adev, &info); > @@ -368,7 +370,7 @@ static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value, > > switch (value) { > case ACPI_RECONFIG_DEVICE_ADD: > - if (i2c_acpi_get_info(adev, &info, &adapter_handle)) > + if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle)) > break;
... the ACPI device added here is physically existent?
> > adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
I suppose that it is always true that adev has been LoadTable()'d from some SSDT? Can't this SSDT be just as broken as my DSDT is? Not that I've seen such a case in the real world, I'm just asking.
Thanks,
Nicolai
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