Date: Tue, 30 Aug 2016 12:36:14 +0000 (UTC) From: Bruce Evans <bde@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r305060 - head/sys/dev/kbdmux Message-ID: <201608301236.u7UCaEl1062549@repo.freebsd.org>
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Author: bde Date: Tue Aug 30 12:36:14 2016 New Revision: 305060 URL: https://svnweb.freebsd.org/changeset/base/305060 Log: Fix keyboard polling "on/off" to support recursion. vt depends on this, and sc will soon depend on it again. The on/off request is passed without modification to lower layers, so the bug was smaller in this layer than in in lower layers (the sequence on;on;off left polling off when it should be on, but the sequence on;on;off;on;off... doesn't allow the interrupt handler to eat the input after an "off" that should't turn off polled mode, provided lower layers don't have the bug, since this layer is virtual. The bug was small in lower layers too. Normally everything is Giant locked for keyboards, and this locks out the interrupt handler in on;on;off;on;off... sequences. However, PR 211884 says that fixing this bug in ukbd in r303765 apparently causes the eating-by-interrupt behaviour that the fix is to prevent. Discussed with: emax Modified: head/sys/dev/kbdmux/kbdmux.c Modified: head/sys/dev/kbdmux/kbdmux.c ============================================================================== --- head/sys/dev/kbdmux/kbdmux.c Tue Aug 30 10:57:19 2016 (r305059) +++ head/sys/dev/kbdmux/kbdmux.c Tue Aug 30 12:36:14 2016 (r305060) @@ -150,9 +150,9 @@ struct kbdmux_state int ks_flags; /* flags */ #define COMPOSE (1 << 0) /* compose char flag */ -#define POLLING (1 << 1) /* polling */ #define TASK (1 << 2) /* interrupt task queued */ + int ks_polling; /* poll nesting count */ int ks_mode; /* K_XLATE, K_RAW, K_CODE */ int ks_state; /* state */ int ks_accents; /* accent key index (> 0) */ @@ -666,7 +666,7 @@ next_code: /* see if there is something in the keyboard queue */ scancode = kbdmux_kbd_getc(state); if (scancode == -1) { - if (state->ks_flags & POLLING) { + if (state->ks_polling != 0) { kbdmux_kbd_t *k; SLIST_FOREACH(k, &state->ks_kbds, next) { @@ -1244,7 +1244,8 @@ kbdmux_clear_state_locked(kbdmux_state_t { KBDMUX_LOCK_ASSERT(state, MA_OWNED); - state->ks_flags &= ~(COMPOSE|POLLING); + state->ks_flags &= ~COMPOSE; + state->ks_polling = 0; state->ks_state &= LOCK_MASK; /* preserve locking key state */ state->ks_accents = 0; state->ks_composed_char = 0; @@ -1304,9 +1305,9 @@ kbdmux_poll(keyboard_t *kbd, int on) KBDMUX_LOCK(state); if (on) - state->ks_flags |= POLLING; + state->ks_polling++; else - state->ks_flags &= ~POLLING; + state->ks_polling--; /* set poll on slave keyboards */ SLIST_FOREACH(k, &state->ks_kbds, next)
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