Input: elantech - fix crc_enabled for Fujitsu H730

The Fujitsu H730 does not work with crc_enabled = 0, even though the
crc_enabled bit in the firmware version indicated it would. When switching
this value to crc_enabled to 1, the touchpad works. This patch uses DMI to
detect H730.

Reported-by: Stefan Valouch <stefan@valouch.com>
Tested-by: Stefan Valouch <stefan@valouch.com>
Tested-by: Alfredo Gemma <alfredo.gemma@gmail.com>
Signed-off-by: Ulrik De Bie <ulrik.debie-os@e2big.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 53ddff91ab2e..ce699eba9adc 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -1451,6 +1451,22 @@ static int elantech_reconnect(struct psmouse *psmouse)
 }
 
 /*
+ * Some hw_version 4 models do not work with crc_disabled
+ */
+static const struct dmi_system_id elantech_dmi_force_crc_enabled[] = {
+#if defined(CONFIG_DMI) && defined(CONFIG_X86)
+        {
+                /* Fujitsu H730 does not work with crc_enabled == 0 */
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "CELSIUS H730"),
+                },
+        },
+#endif
+        { }
+};
+
+/*
  * Some hw_version 3 models go into error state when we try to set
  * bit 3 and/or bit 1 of r10.
  */
@@ -1525,7 +1541,8 @@ static int elantech_set_properties(struct elantech_data *etd)
          * The signatures of v3 and v4 packets change depending on the
          * value of this hardware flag.
          */
-        etd->crc_enabled = ((etd->fw_version & 0x4000) == 0x4000);
+        etd->crc_enabled = (etd->fw_version & 0x4000) == 0x4000 ||
+                           dmi_check_system(elantech_dmi_force_crc_enabled);
 
         /* Enable real hardware resolution on hw_version 3 ? */
         etd->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);