Re: pms(4): disable parity checking for specific elantech fw

[sxvghd]

On 2020-08-08 22:47, Marcus Glocker wrote:

Can we maybe add a small comment explaining the inverted parity bits
behaviour on cold boot for this firmware version?

Sure thing.

Index: pms.c
===================================================================
RCS file: /cvs/src/sys/dev/pckbc/pms.c,v
retrieving revision 1.93
diff -u -p -u -r1.93 pms.c
--- pms.c       4 Jul 2020 10:39:25 -0000       1.93
+++ pms.c       10 Aug 2020 12:58:01 -0000
@@ -2292,7 +2292,12 @@ pms_sync_elantech_v1(struct pms_softc *s
        }

        if (data < 0 || data >= nitems(elantech->parity) ||
-           elantech->parity[data] != p)
+           /*
+            * FW 0x20022 sends inverted parity bits on cold boot, returning
+            * to normal after suspend & resume, so the parity check is
+            * disabled for this one.
+            */
+           (elantech->fw_version != 0x20022 && elantech->parity[data] != p))
                return (-1);

        return (0);