platform/x86: dell-wmi-sysman: work around for BIOS bug

BIOS sets incorrect value (zero) when SET value passed for integer
attribute with + sign. Added workaround to remove + sign before passing
input to BIOS.

Co-developed-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Co-developed-by: Prasanth KSR <prasanth.ksr@dell.com>
Signed-off-by: Prasanth KSR <prasanth.ksr@dell.com>
Signed-off-by: Divya Bharathi <divya.bharathi@dell.com>
Link: https://lore.kernel.org/r/20201202131935.307372-1-divya.bharathi@dell.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/dell-wmi-sysman/int-attributes.c b/drivers/platform/x86/dell-wmi-sysman/int-attributes.c
index ea773d8e8d3a788f1ea477acd604e22308888342..75aedbb733be2ccaab6f13de34c1a7a1c8a1399c 100644 (file)
--- a/drivers/platform/x86/dell-wmi-sysman/int-attributes.c
+++ b/drivers/platform/x86/dell-wmi-sysman/int-attributes.c
@@ -39,7 +39,7 @@ static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *a
  * @instance_id: The instance on which input is validated
  * @buf: Input value
  */
-static int validate_integer_input(int instance_id, const char *buf)
+static int validate_integer_input(int instance_id, char *buf)
 {
        int in_val;
        int ret;
@@ -51,6 +51,12 @@ static int validate_integer_input(int instance_id, const char *buf)
                        in_val > wmi_priv.integer_data[instance_id].max_value)
                return -EINVAL;
 
+       /* workaround for BIOS error.
+        * validate input to avoid setting 0 when integer input passed with + sign
+        */
+       if (*buf == '+')
+               memmove(buf, (buf + 1), strlen(buf + 1) + 1);
+
        return ret;
 }