mfd: kempld: Switch back to earlier ->init() behavior

commit 309e65d151ab9be1e7b01d822880cd8c4e611dff upstream.

Commit 9e36775c22c7 ("mfd: kempld: Remove custom DMI matching code")
removes the ability to load the driver if no matching system DMI data
is found. Before this commit the driver could be loaded using
alternative methods such as ACPI or `force_device_id` in the absence
of a matching system DMI entry.

Restore this ability while keeping the refactored
`platform_device_info` table.

Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/7d2c7e92253d851194a781720051536cca2722b8.camel@secunet.com
Signed-off-by: Lee Jones <lee@kernel.org>
Cc: Michael Brunner <Michael.Brunner@jumptec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mfd/kempld-core.c b/drivers/mfd/kempld-core.c
index 8a332852bf97d08b061a6ca3a12a6ed60fa3784e..fb069026413802a774d376191e0a9ca390f8b9d8 100644 (file)
--- a/drivers/mfd/kempld-core.c
+++ b/drivers/mfd/kempld-core.c
@@ -779,22 +779,26 @@ MODULE_DEVICE_TABLE(dmi, kempld_dmi_table);
 static int __init kempld_init(void)
 {
        const struct dmi_system_id *id;
-       int ret = -ENODEV;
 
-       for (id = dmi_first_match(kempld_dmi_table); id; id = dmi_first_match(id + 1)) {
-               /* Check, if user asked for the exact device ID match */
-               if (force_device_id[0] && !strstr(id->ident, force_device_id))
-                       continue;
-
-               ret = kempld_create_platform_device(&kempld_platform_data_generic);
-               if (ret)
-                       continue;
-
-               break;
+       /*
+        * This custom DMI iteration allows the driver to be initialized in three ways:
+        * - When a forced_device_id string matches any ident in the kempld_dmi_table,
+        *   regardless of whether the DMI device is present in the system dmi table.
+        * - When a matching entry is present in the DMI system tabe.
+        * - Through alternative mechanisms like ACPI.
+        */
+       if (force_device_id[0]) {
+               for (id = kempld_dmi_table; id->matches[0].slot != DMI_NONE; id++)
+                       if (strstr(id->ident, force_device_id))
+                               if (!kempld_create_platform_device(&kempld_platform_data_generic))
+                                       break;
+               if (id->matches[0].slot == DMI_NONE)
+                       return -ENODEV;
+       } else {
+               for (id = dmi_first_match(kempld_dmi_table); id; id = dmi_first_match(id+1))
+                       if (kempld_create_platform_device(&kempld_platform_data_generic))
+                               break;
        }
-       if (ret)
-               return ret;
-
        return platform_driver_register(&kempld_driver);
 }