From d6ac466168aa4b1a6217e4b023d3fe23a8bcafe7 Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Thu, 19 Dec 2019 19:03:45 +0900 Subject: [PATCH] serdev: Don't claim unsupported ACPI serial devices 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 Acked-by: Hans de Goede Acked-by: Johan Hovold Cc: Rob Herring Link: https://lore.kernel.org/r/20191219100345.911093-1-punit1.agrawal@toshiba.co.jp Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serdev/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index a0ac16ee6575..a9719858c950 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -582,6 +582,12 @@ static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, 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) { @@ -591,6 +597,10 @@ static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, 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); }