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Message-ID: <1803515.qlJg32fkH4@linux-5eaq.site>
Date: Wed, 30 Jan 2013 14:28:47 +0100
From: Oliver Neukum <oneukum@...e.de>
To: Kurachkin Michail <Michail.Kurachkin@...mwad.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Kuten Ivan <Ivan.Kuten@...mwad.com>,
"benavi@...vell.com" <benavi@...vell.com>,
Palstsiuk Viktar <Viktar.Palstsiuk@...mwad.com>
Subject: Re: TDM bus support in Linux Kernel [PATCH]
On Wednesday 30 January 2013 12:37:25 Kurachkin Michail wrote:
> Hi Greg,
>
> I followed your recommendations and created a diff using Linux 3.8-rc5 sources. Please review it and give your comments.
Part #3
+/*
+ * method "open" for character device
+ */
+static int slic_chr_open(struct inode *inode, struct file *file)
+{
+ struct slic_chr_dev *chr_dev;
+ struct si3226x_slic *slic;
+ struct si3226x_line *line;
+ struct tdm_device *tdm_dev;
+ struct tdm_voice_channel *ch;
+ int status = -ENXIO;
+
+ mutex_lock(&slic_chr_dev_lock);
+
+ list_for_each_entry(chr_dev, &slic_chr_dev_list, list) {
+ switch (chr_dev->type) {
+ case SLIC_CHR_DEV:
+ slic = dev_get_drvdata(chr_dev->dev);
+
+ if (slic->devt != inode->i_rdev)
+ continue;;
+
+ if (slic->file_opened) {
+ status = -EBUSY;
+ goto out;
+ }
+
+ slic->file_opened = 1;
+ status = 0;
+ break;
+
+ case LINE_CHR_DEV:
+ line = dev_get_drvdata(chr_dev->dev);
+ tdm_dev = line->tdm_dev;
+
+ if (line->devt != inode->i_rdev)
+ continue;
+
+ if (line->file_opened) {
+ status = -EBUSY;
+ goto out;
+ }
+
+ line->audio_buffer_size = tdm_get_voice_block_size(tdm_dev);
+
+ line->rx_buffer = kzalloc(line->audio_buffer_size, GFP_KERNEL);
+ if (!line->rx_buffer) {
+ status = -ENOMEM;
+ goto out;
+ }
+
+ line->tx_buffer = kzalloc(line->audio_buffer_size, GFP_KERNEL);
+ if (!line->tx_buffer) {
+ status = -ENOMEM;
memory leak of line->rx_buffer
+ goto out;
+ }
+
+ /* store pointer to transmit wait_queue_head_t for use in poll() */
+ ch = tdm_dev->ch;
+ line->tx_wait_queue = &ch->tx_queue;
+ line->rx_wait_queue = &ch->rx_queue;
+ line->file_opened = 1;
+ status = 0;
+
+ break;
+ }
+
+ file->private_data = chr_dev;
+ status = 0;
+ goto out;
a bit pointless
+ }
+
+out:
+ mutex_unlock(&slic_chr_dev_lock);
+ return status;
+}
+/*
+ * method "ioctl" for character device
+ */
+static long
+slic_chr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct slic_chr_dev *chr_dev = file->private_data;
+ struct si3226x_slic *slic;
+ struct si3226x_line *line;
+ int status = -ENXIO;
+
+ if (_IOC_TYPE(cmd) != SI3226X_IOC_MAGIC)
+ return -ENOTTY;
+
+ mutex_lock(&slic_chr_dev_lock);
+
+ if (!file->private_data) {
+ status = -EPERM;
-EPERM?
+ goto out;
+ }
+
+ switch(chr_dev->type) {
+ case SLIC_CHR_DEV:
+ slic = dev_get_drvdata(chr_dev->dev);
+ if (!slic->file_opened) {
+ status = -ENODEV;
+ goto out;
+ }
+
+ status = slic_control(slic, cmd, arg);
+ break;
+
+ case LINE_CHR_DEV:
+ line = dev_get_drvdata(chr_dev->dev);
+ if (!line->file_opened) {
+ status = -ENODEV;
+ goto out;
+ }
+
+ status = line_control(line, cmd, arg);
+ break;
+ }
+
+out:
+ mutex_unlock(&slic_chr_dev_lock);
+ return status;
+}
+/*
+ * method "read" for character device
+ */
+static ssize_t
+slic_chr_read(struct file *file, char *buff, size_t count, loff_t *offp)
+{
+ struct slic_chr_dev *chr_dev = file->private_data;
+ struct si3226x_line *line;
+ struct tdm_device *tdm_dev;
+ int rc;
+
+ if (!file->private_data)
+ return -EPERM;
+
+ if(chr_dev->type != LINE_CHR_DEV)
+ return -EPERM;
+
+ mutex_lock(&slic_chr_dev_lock);
+
+ line = dev_get_drvdata(chr_dev->dev);
+ tdm_dev = line->tdm_dev;
+
+ if (count != line->audio_buffer_size) {
+ rc = -ENODATA;
+ goto out;
+ }
+
+ rc = tdm_recv(tdm_dev, line->rx_buffer);
+ if (rc) {
+ rc = -EFAULT;
EFAULT is usually not what you return upon a read error.
+ goto out;
+ }
+
+ rc = copy_to_user(buff, line->rx_buffer, count);
+ if (rc) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ rc = count;
+out:
+ mutex_unlock(&slic_chr_dev_lock);
+ return rc;
+}
--
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