On Thu, Dec 15, 2022 at 4:51 PM Mario Limonciello <mario.limonciello@xxxxxxx> wrote: > > Microsoft introduced support in Windows XP for blocking port I/O > to various regions. For Windows compatibility ACPICA has adopted > the same protections and will disallow writes to those > (presumably) the same regions. > > On some systems the AML included with the firmware will issue 4 byte > long writes to 0x80. These writes aren't making it over because of this > blockage. The first 4 byte write attempt is rejected, and then > subsequently 1 byte at a time each offset is tried. The first at 0x80 > works, but then the next 3 bytes are rejected. > > This manifests in bizarre failures for devices that expected the AML to > write all 4 bytes. Trying the same AML on Windows 10 or 11 doesn't hit > this failure and all 4 bytes are written. > > Either some of these regions were wrong or some point after Windows XP > some of these regions blocks have been lifted. > > In the last 15 years there doesn't seem to be any reports popping up of > this error in the Windows event viewer anymore. There is no documentation > at Microsoft's developer site indicating that Windows ACPI interpreter > blocks these regions. Between the lack of documentation and the fact that > the writes actually do work in Windows 10 and 11, it's quite likely > Windows doesn't actually enforce this anymore. > > So to help the issue, only enforce Windows XP specific entries if the > latest _OSI supported is Windows XP. Continue to enforce the > ALWAYS_ILLEGAL entries. > > Link: https://github.com/acpica/acpica/pull/817 > Fixes: 7f0719039085 ("ACPICA: New: I/O port protection") > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> > --- > drivers/acpi/acpica/hwvalid.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/acpi/acpica/hwvalid.c b/drivers/acpi/acpica/hwvalid.c > index 915b26448d2c..0d392e7b0747 100644 > --- a/drivers/acpi/acpica/hwvalid.c > +++ b/drivers/acpi/acpica/hwvalid.c > @@ -23,8 +23,8 @@ acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width); > * > * The table is used to implement the Microsoft port access rules that > * first appeared in Windows XP. Some ports are always illegal, and some > - * ports are only illegal if the BIOS calls _OSI with a win_XP string or > - * later (meaning that the BIOS itelf is post-XP.) > + * ports are only illegal if the BIOS calls _OSI with nothing newer than > + * the specific _OSI strings. > * > * This provides ACPICA with the desired port protections and > * Microsoft compatibility. > @@ -145,7 +145,8 @@ acpi_hw_validate_io_request(acpi_io_address address, u32 bit_width) > > /* Port illegality may depend on the _OSI calls made by the BIOS */ > > - if (acpi_gbl_osi_data >= port_info->osi_dependency) { > + if (port_info->osi_dependency == ACPI_ALWAYS_ILLEGAL || > + acpi_gbl_osi_data == port_info->osi_dependency) { > ACPI_DEBUG_PRINT((ACPI_DB_VALUES, > "Denied AML access to port 0x%8.8X%8.8X/%X (%s 0x%.4X-0x%.4X)\n", > ACPI_FORMAT_UINT64(address), > -- Applied as 6.3 material, thanks!
