From eb9d84b0ffe39893cb23b0b6712bbe3637fa25fa Mon Sep 17 00:00:00 2001
From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Date: Sun, 24 Apr 2022 19:24:28 +0900
Subject: [PATCH] ALSA: fireworks: fix wrong return count shorter than expected by 4 bytes
Git-commit: eb9d84b0ffe39893cb23b0b6712bbe3637fa25fa
Patch-mainline: v5.18-rc6
References: git-fixes

ALSA fireworks driver has a bug in its initial state to return count
shorter than expected by 4 bytes to userspace applications when handling
response frame for Echo Audio Fireworks transaction. It's due to missing
addition of the size for the type of event in ALSA firewire stack.

Fixes: 555e8a8f7f14 ("ALSA: fireworks: Add command/response functionality into hwdep interface")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220424102428.21109-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/firewire/fireworks/fireworks_hwdep.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/firewire/fireworks/fireworks_hwdep.c b/sound/firewire/fireworks/fireworks_hwdep.c
index 626c0c34b0b6..3a53914277d3 100644
--- a/sound/firewire/fireworks/fireworks_hwdep.c
+++ b/sound/firewire/fireworks/fireworks_hwdep.c
@@ -34,6 +34,7 @@ hwdep_read_resp_buf(struct snd_efw *efw, char __user *buf, long remained,
 	type = SNDRV_FIREWIRE_EVENT_EFW_RESPONSE;
 	if (copy_to_user(buf, &type, sizeof(type)))
 		return -EFAULT;
+	count += sizeof(type);
 	remained -= sizeof(type);
 	buf += sizeof(type);
 
-- 
2.31.1