[PATCH 5.14 329/334] ACPI: PRM: Find PRMT table before parsing it

Greg Kroah-Hartman
2021-09-13T14:50:15Z

From: Aubrey Li <aubrey.li@intel.com>

commit 3265cc3ec52e75fc8daf189954cebda27ad26b2e upstream.

Find and verify PRMT before parsing it, which eliminates a
warning on machines without PRMT:

[ 7.197173] ACPI: PRMT not present

Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: 5.14+ <stable@vger.kernel.org> # 5.14+
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/acpi/prmt.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/acpi/prmt.c
+++ b/drivers/acpi/prmt.c
@@ -288,10 +288,18 @@ invalid_guid:

void __init init_prmt(void)
{
+ struct acpi_table_header *tbl;
acpi_status status;
- int mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) +
+ int mc;
+
+ status = acpi_get_table(ACPI_SIG_PRMT, 0, &tbl);
+ if (ACPI_FAILURE(status))
+ return;
+
+ mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) +
sizeof (struct acpi_table_prmt_header),
0, acpi_parse_prmt, 0);
+ acpi_put_table(tbl);
/*
* Return immediately if PRMT table is not present or no PRM module found.
*/