ACPI: LPSS: Use kstrtol() instead of simple_strtol()

The simple_strtol() function is not reliable in some situation, since
it does not check for the range overflow. Use kstrtol() instead.

While at it, modify the code to avoid evaluating _SEM unnecessarily
if uid_str is NULL or kstrtol() fails to convert that string to a
nonzero number.
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
[ rjw: Check uid right after calling kstrtol() ]
[ rjw: Rewrite subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpi_lpss.c

@@ -186,13 +186,12 @@ static void byt_i2c_setup(struct lpss_private_data *pdata)
 	long uid = 0;
 
 	/* Expected to always be true, but better safe then sorry */
-	if (uid_str)
-		uid = simple_strtol(uid_str, NULL, 10);
-
-	/* Detect I2C bus shared with PUNIT and ignore its d3 status */
-	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
-	if (ACPI_SUCCESS(status) && shared_host && uid)
-		pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
+	if (uid_str && !kstrtol(uid_str, 10, &uid) && uid) {
+		/* Detect I2C bus shared with PUNIT and ignore its d3 status */
+		status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
+		if (ACPI_SUCCESS(status) && shared_host)
+			pmc_atom_d3_mask &= ~(BIT_LPSS2_F1_I2C1 << (uid - 1));
+	}
 
 	lpss_deassert_reset(pdata);