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From:   Aubrey Li <aubrey.li@intel.com>
To:     rjw@rjwysocki.net, lenb@kernel.org
Cc:     linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Aubrey Li <aubrey.li@intel.com>,
        Aubrey Li <aubrey.li@linux.intel.com>
Subject: [PATCH] ACPI/PRM: Deal with table not present or no module found
Date:   Fri,  6 Aug 2021 08:46:24 +0800
Message-Id: <1628210784-136676-1-git-send-email-aubrey.li@intel.com>
Precedence: bulk

On the system PRMT table is not present, dmesg output:

	$ dmesg | grep PRM
	[    1.532237] ACPI: PRMT not present
	[    1.532237] PRM: found 4294967277 modules

The result of acpi_table_parse_entries need to be checked and return
immediately if PRMT table is not present or no PRM module found.

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
---
 drivers/acpi/prmt.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
index 31cf9ae..1f6007a 100644
--- a/drivers/acpi/prmt.c
+++ b/drivers/acpi/prmt.c
@@ -292,6 +292,12 @@ void __init init_prmt(void)
 	int mc = acpi_table_parse_entries(ACPI_SIG_PRMT, sizeof(struct acpi_table_prmt) +
 					  sizeof (struct acpi_table_prmt_header),
 					  0, acpi_parse_prmt, 0);
+	/*
+	 * Return immediately if PRMT table is not present or no PRM module found.
+	 */
+	if (mc <= 0)
+		return;
+
 	pr_info("PRM: found %u modules\n", mc);
 
 	status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
-- 
2.7.4