Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 141C14EF153; Thu, 17 Sep 2026 17:16:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789665419; cv=none; b=GQlf7SpYO/Th3dDG/iFEhs7m61eLFDtRvJ73KqrjrZJo1KRycHaek2xOKpBhpslVEo2R1VhufYKFPUpIZbu5jwlaYdiMv6f7UIGOIQIPxT1MJ4qy4QSnvRL3wgO31RrDgnbVdRmj3yysMcOtq0Z+i0sge6tQgpS5JFCwG96qRHE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789665419; c=relaxed/simple; bh=A3nkvJ/+YEN7eEUuZC4pWT4ODvciv0jWkP9SmyZnXiw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KNTl/RqBWCgC3fcnfVXMqKSzbz+fqmvJZ28dumQbhqga9LP+axLqUA2DI56AjUyTigpUDMrpzcAaoMVsJhs2HCdr1iWIl8b/WJQNAAs4CIa+OjpCZzbQqZWVPGAFam8X8nukAKzDpk/+dD85UesdmBmFLWJPzlrvmrQLIJsMVao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=D+tenSsu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="D+tenSsu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5DFAB1F00893; Thu, 17 Sep 2026 17:16:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789665417; bh=h8Sz9Qj8p4mQgrWDfY2zzfPgk09s5gmQ6qoWtju05cA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=D+tenSsutKJcyCCHBeIR91Xqqtw4lxaQqPE/aHCv5UyJeP2jMcAv02essHULCGFpW QzZh2alTti8YcP+6A6cbHNuFDhZx15wEuJM1hkjvN11/ZUk+5akziRtICjqBqSjIoa LE40rCGn+1yL+00vqpU3bd428JxkOfaAXSS5W8K0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, HyeongJun An , Takashi Iwai , Sasha Levin Subject: [PATCH 6.18 0699/1250] ALSA: dummy: Report a change when one capture switch channel moves Date: Thu, 17 Sep 2026 16:08:14 +0100 Message-ID: <20260917151610.836611313@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151551.901433442@linuxfoundation.org> References: <20260917151551.901433442@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: HyeongJun An [ Upstream commit 83162eeaf78c71ff6f6fa31dc95e3b6e90ee593f ] The snd_dummy_capsrc_put() builds its change flag with &&, so it reports a change only when both channels move at once. Writing a single channel stores the new value and returns 0, the control core then sends no SNDRV_CTL_EVENT_MASK_VALUE, and a second reader keeps showing the old setting until it polls again. The volume put a few lines above compares the same pair of channels with ||. The mixer selftest already reports this. With snd-dummy loaded it fails event_missing on all five capture switches: # CD Capture Switch.1 orig 0 read 1, is_volatile 0 not ok 13 event_missing.Dummy.9 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Assisted-by: Claude:claude-opus-5 Signed-off-by: HyeongJun An Link: https://patch.msgid.link/20260901153921.3971-1-sammiee5311@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/drivers/dummy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c index bf20c1009707f..b871fa34bf1bd 100644 --- a/sound/drivers/dummy.c +++ b/sound/drivers/dummy.c @@ -782,7 +782,7 @@ static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_el left = ucontrol->value.integer.value[0] & 1; right = ucontrol->value.integer.value[1] & 1; guard(spinlock_irq)(&dummy->mixer_lock); - change = dummy->capture_source[addr][0] != left && + change = dummy->capture_source[addr][0] != left || dummy->capture_source[addr][1] != right; dummy->capture_source[addr][0] = left; dummy->capture_source[addr][1] = right; -- 2.53.0