On Thu, May 16, 2024 at 12:22 PM Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > On Wed, May 15, 2024 at 09:40:54PM +0200, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > It is reported that _DSM evaluation fails in ucsi_acpi_dsm() on Lenovo > > IdeaPad Pro 5 due to a missing address space handler for the EC address > > space: > > > > ACPI Error: No handler for Region [ECSI] (000000007b8176ee) [EmbeddedControl] (20230628/evregion-130) > > > > This happens because if there is no ECDT, the EC driver only registers > > the EC address space handler for operation regions defined in the EC > > device scope of the ACPI namespace while the operation region being > > accessed by the _DSM in question is located beyond that scope. > > > > To address this, modify the ACPI EC driver to install the EC address > > space handler at the root of the ACPI namespace for the first EC that > > can be found regardless of whether or not an ECDT is present. > > > > Note that this change is consistent with some examples in the ACPI > > specification in which EC operation regions located outside the EC > > device scope are used (for example, see Section 9.17.15 in ACPI 6.5), > > so the current behavior of the EC driver is arguably questionable. > > ... > > > - status = acpi_install_address_space_handler_no_reg(ec->handle, > > + status = acpi_install_address_space_handler_no_reg(scope_handle, > > ACPI_ADR_SPACE_EC, > > &acpi_ec_space_handler, > > NULL, ec); > > Looking at this... > > > if (ACPI_FAILURE(acpi_remove_address_space_handler( > > + scope_handle, > > + ACPI_ADR_SPACE_EC, > > + &acpi_ec_space_handler))) > > ...and this, I believe you can move scope_handle to the previous line and align > the rest for the sake of consistency and slightly better readability. Well, I prefer to cut a separate cleanup patch to make this more consistent.
