ASoC: Intel: Skylake: Check for NHLT ACPI header signature

In certain buggy BIOS acpi_evaluate_dsm() may not return the correct
NHLT table, so check the NHLT table header signature before accessing
it.

Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Signed-off-by: Guneshwor Singh <guneshwor.o.singh@intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Pankaj Bharadiya 2017-11-07 16:16:21 +05:30 committed by Mark Brown
parent f8e0665211
commit 3b47c9dc75
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 9 additions and 0 deletions

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@ -20,6 +20,8 @@
#include <linux/pci.h>
#include "skl.h"
#define NHLT_ACPI_HEADER_SIG "NHLT"
/* Unique identification for getting NHLT blobs */
static guid_t osc_guid =
GUID_INIT(0xA69F886E, 0x6CEB, 0x4594,
@ -45,6 +47,13 @@ struct nhlt_acpi_table *skl_nhlt_init(struct device *dev)
memremap(nhlt_ptr->min_addr, nhlt_ptr->length,
MEMREMAP_WB);
ACPI_FREE(obj);
if (nhlt_table && (strncmp(nhlt_table->header.signature,
NHLT_ACPI_HEADER_SIG,
strlen(NHLT_ACPI_HEADER_SIG)) != 0)) {
memunmap(nhlt_table);
dev_err(dev, "NHLT ACPI header signature incorrect\n");
return NULL;
}
return nhlt_table;
}