From e636c8d336489bf3eed5878299e6cc045bbad077 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:17:29 +0000
Subject: [PATCH] debug lk
---
kernel/sound/firewire/tascam/tascam-hwdep.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 104 insertions(+), 16 deletions(-)
diff --git a/kernel/sound/firewire/tascam/tascam-hwdep.c b/kernel/sound/firewire/tascam/tascam-hwdep.c
index 4e4c1e9..6f38335 100644
--- a/kernel/sound/firewire/tascam/tascam-hwdep.c
+++ b/kernel/sound/firewire/tascam/tascam-hwdep.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* tascam-hwdep.c - a part of driver for TASCAM FireWire series
*
* Copyright (c) 2015 Takashi Sakamoto
- *
- * Licensed under the terms of the GNU General Public License, version 2.
*/
/*
@@ -16,18 +15,95 @@
#include "tascam.h"
+static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,
+ long count, loff_t *offset)
+ __releases(&tscm->lock)
+{
+ struct snd_firewire_event_lock_status event = {
+ .type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
+ };
+
+ event.status = (tscm->dev_lock_count > 0);
+ tscm->dev_lock_changed = false;
+ count = min_t(long, count, sizeof(event));
+
+ spin_unlock_irq(&tscm->lock);
+
+ if (copy_to_user(buf, &event, count))
+ return -EFAULT;
+
+ return count;
+}
+
+static long tscm_hwdep_read_queue(struct snd_tscm *tscm, char __user *buf,
+ long remained, loff_t *offset)
+ __releases(&tscm->lock)
+{
+ char __user *pos = buf;
+ unsigned int type = SNDRV_FIREWIRE_EVENT_TASCAM_CONTROL;
+ struct snd_firewire_tascam_change *entries = tscm->queue;
+ long count;
+
+ // At least, one control event can be copied.
+ if (remained < sizeof(type) + sizeof(*entries)) {
+ spin_unlock_irq(&tscm->lock);
+ return -EINVAL;
+ }
+
+ // Copy the type field later.
+ count = sizeof(type);
+ remained -= sizeof(type);
+ pos += sizeof(type);
+
+ while (true) {
+ unsigned int head_pos;
+ unsigned int tail_pos;
+ unsigned int length;
+
+ if (tscm->pull_pos == tscm->push_pos)
+ break;
+ else if (tscm->pull_pos < tscm->push_pos)
+ tail_pos = tscm->push_pos;
+ else
+ tail_pos = SND_TSCM_QUEUE_COUNT;
+ head_pos = tscm->pull_pos;
+
+ length = (tail_pos - head_pos) * sizeof(*entries);
+ if (remained < length)
+ length = rounddown(remained, sizeof(*entries));
+ if (length == 0)
+ break;
+
+ spin_unlock_irq(&tscm->lock);
+ if (copy_to_user(pos, &entries[head_pos], length))
+ return -EFAULT;
+
+ spin_lock_irq(&tscm->lock);
+
+ tscm->pull_pos = tail_pos % SND_TSCM_QUEUE_COUNT;
+
+ count += length;
+ remained -= length;
+ pos += length;
+ }
+
+ spin_unlock_irq(&tscm->lock);
+
+ if (copy_to_user(buf, &type, sizeof(type)))
+ return -EFAULT;
+
+ return count;
+}
+
static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
loff_t *offset)
{
struct snd_tscm *tscm = hwdep->private_data;
DEFINE_WAIT(wait);
- union snd_firewire_event event = {
- .lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
- };
spin_lock_irq(&tscm->lock);
- while (!tscm->dev_lock_changed) {
+ while (!tscm->dev_lock_changed && tscm->push_pos == tscm->pull_pos) {
prepare_to_wait(&tscm->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
spin_unlock_irq(&tscm->lock);
schedule();
@@ -37,15 +113,15 @@
spin_lock_irq(&tscm->lock);
}
- event.lock_status.status = (tscm->dev_lock_count > 0);
- tscm->dev_lock_changed = false;
-
- spin_unlock_irq(&tscm->lock);
-
- count = min_t(long, count, sizeof(event.lock_status));
-
- if (copy_to_user(buf, &event, count))
- return -EFAULT;
+ // NOTE: The acquired lock should be released in callee side.
+ if (tscm->dev_lock_changed) {
+ count = tscm_hwdep_read_locked(tscm, buf, count, offset);
+ } else if (tscm->push_pos != tscm->pull_pos) {
+ count = tscm_hwdep_read_queue(tscm, buf, count, offset);
+ } else {
+ spin_unlock_irq(&tscm->lock);
+ count = 0;
+ }
return count;
}
@@ -59,7 +135,7 @@
poll_wait(file, &tscm->hwdep_wait, wait);
spin_lock_irq(&tscm->lock);
- if (tscm->dev_lock_changed)
+ if (tscm->dev_lock_changed || tscm->push_pos != tscm->pull_pos)
events = EPOLLIN | EPOLLRDNORM;
else
events = 0;
@@ -123,6 +199,14 @@
return err;
}
+static int tscm_hwdep_state(struct snd_tscm *tscm, void __user *arg)
+{
+ if (copy_to_user(arg, tscm->state, sizeof(tscm->state)))
+ return -EFAULT;
+
+ return 0;
+}
+
static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
{
struct snd_tscm *tscm = hwdep->private_data;
@@ -147,6 +231,8 @@
return hwdep_lock(tscm);
case SNDRV_FIREWIRE_IOCTL_UNLOCK:
return hwdep_unlock(tscm);
+ case SNDRV_FIREWIRE_IOCTL_TASCAM_STATE:
+ return tscm_hwdep_state(tscm, (void __user *)arg);
default:
return -ENOIOCTLCMD;
}
@@ -185,5 +271,7 @@
hwdep->private_data = tscm;
hwdep->exclusive = true;
+ tscm->hwdep = hwdep;
+
return err;
}
--
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