From: Punit Agrawal punit1.agrawal@toshiba.co.jp
commit c5ee0b3104e0b292d353e63fd31cb8c692645d8c upstream.
Serdev sub-system claims all ACPI serial devices that are not already initialised. As a result, no device node is created for serial ports on certain boards such as the Apollo Lake based UP2. This has the unintended consequence of not being able to raise the login prompt via serial connection.
Introduce a blacklist to reject ACPI serial devices that should not be claimed by serdev sub-system. Add the peripheral ids for Intel HS UART to the blacklist to bring back serial port on SoCs carrying them.
Cc: stable@vger.kernel.org Signed-off-by: Punit Agrawal punit1.agrawal@toshiba.co.jp Acked-by: Hans de Goede hdegoede@redhat.com Acked-by: Johan Hovold johan@kernel.org Cc: Rob Herring robh@kernel.org Link: https://lore.kernel.org/r/20191219100345.911093-1-punit1.agrawal@toshiba.co.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serdev/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -526,6 +526,12 @@ static acpi_status acpi_serdev_register_ return AE_OK; }
+static const struct acpi_device_id serdev_acpi_devices_blacklist[] = { + { "INT3511", 0 }, + { "INT3512", 0 }, + { }, +}; + static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, void *data, void **return_value) { @@ -535,6 +541,10 @@ static acpi_status acpi_serdev_add_devic if (acpi_bus_get_device(handle, &adev)) return AE_OK;
+ /* Skip if black listed */ + if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist)) + return AE_OK; + return acpi_serdev_register_device(ctrl, adev); }