spi/acpi: fix incorrect ACPI parent check

The ACPI device object parsing code for SPI slaves enumerates the
entire ACPI namespace to look for devices that refer to the master
in question via the 'resource_source' field in the 'SPISerialBus'
resource. If that field does not refer to a valid ACPI device or
if it refers to the wrong SPI master, we should disregard the
device.

Current, the valid device check is wrong, since it gets the
polarity of 'status' wrong. This could cause issues if the
'resource_source' field is bogus but parent_handle happens to
refer to the correct master (which is not entirely imaginary
since this code runs in a loop)

So test for ACPI_FAILURE() instead, to make the code more
self explanatory.

Fixes: 4c3c59544f33 ("spi/acpi: enumerate all SPI slaves in the namespace")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: andy.shevchenko@gmail.com
Cc: masahisa.kojima@linaro.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: linux-acpi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 01a40bcfc352c5a186d1c7016a2969e3ca46b4b2..a31e1e291335915574f25836b74eaf32b13ef212 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1907,7 +1907,7 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
                                                 sb->resource_source.string_ptr,
                                                 &parent_handle);
 
-                       if (!status ||
+                       if (ACPI_FAILURE(status) ||
                            ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
                                return -ENODEV;