/*
 *  PCM DRM helpers
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License version 2 as
 *   published by the Free Software Foundation.
 */
#include <linux/export.h>
#include <linux/types.h>
#include <sound/asoundef.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pcm_iec958.h>

static int create_iec958_consumer(uint rate, uint sample_width,
				  u8 *cs, size_t len)
{
	unsigned int fs, ws;

	if (len < 4)
		return -EINVAL;

	switch (rate) {
	case 32000:
		fs = IEC958_AES3_CON_FS_32000;
		break;
	case 44100:
		fs = IEC958_AES3_CON_FS_44100;
		break;
	case 48000:
		fs = IEC958_AES3_CON_FS_48000;
		break;
	case 88200:
		fs = IEC958_AES3_CON_FS_88200;
		break;
	case 96000:
		fs = IEC958_AES3_CON_FS_96000;
		break;
	case 176400:
		fs = IEC958_AES3_CON_FS_176400;
		break;
	case 192000:
		fs = IEC958_AES3_CON_FS_192000;
		break;
	default:
		return -EINVAL;
	}

	if (len > 4) {
		switch (sample_width) {
		case 16:
			ws = IEC958_AES4_CON_WORDLEN_20_16;
			break;
		case 18:
			ws = IEC958_AES4_CON_WORDLEN_22_18;
			break;
		case 20:
			ws = IEC958_AES4_CON_WORDLEN_20_16 |
			     IEC958_AES4_CON_MAX_WORDLEN_24;
			break;
		case 24:
		case 32: /* Assume 24-bit width for 32-bit samples. */
			ws = IEC958_AES4_CON_WORDLEN_24_20 |
			     IEC958_AES4_CON_MAX_WORDLEN_24;
			break;

		default:
			return -EINVAL;
		}
	}

	memset(cs, 0, len);

	cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
	cs[1] = IEC958_AES1_CON_GENERAL;
	cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
	cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs;

	if (len > 4)
		cs[4] = ws;

	return len;
}

/**
 * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
 * @runtime: pcm runtime structure with ->rate filled in
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Create the consumer format channel status data in @cs of maximum size
 * @len corresponding to the parameters of the PCM runtime @runtime.
 *
 * Drivers may wish to tweak the contents of the buffer after creation.
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
	size_t len)
{
	return create_iec958_consumer(runtime->rate,
				      snd_pcm_format_width(runtime->format),
				      cs, len);
}
EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);

/**
 * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status
 * @hw_params: the hw_params instance for extracting rate and sample format
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Create the consumer format channel status data in @cs of maximum size
 * @len corresponding to the parameters of the PCM runtime @runtime.
 *
 * Drivers may wish to tweak the contents of the buffer after creation.
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
					     u8 *cs, size_t len)
{
	return create_iec958_consumer(params_rate(params), params_width(params),
				      cs, len);
}
EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);
/b><form method='get'><input type='hidden' name='id' value='91539eb1fda2d530d3b268eef542c5414e54bf1a'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Iago Abal &lt;mail@iagoabal.eu&gt;</td><td class='right'>2017-01-11 14:00:21 +0100</td></tr>
<tr><th>committer</th><td>Vinod Koul &lt;vinod.koul@intel.com&gt;</td><td class='right'>2017-01-25 15:35:11 +0530</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/fsl/imx-pcm-fiq.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/soc/fsl/imx-pcm-fiq.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>960f5ca6342ad20837aff18aad6e8ecd7da32fd6</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/soc/fsl/imx-pcm-fiq.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>sound/soc/fsl/imx-pcm-fiq.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/fsl/imx-pcm-fiq.c?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/fsl/imx-pcm-fiq.c?id=91539eb1fda2d530d3b268eef542c5414e54bf1a&amp;id2=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>diff</a>)</td></tr></table>
<div class='commit-subject'>dmaengine: pl330: fix double lock</div><div class='commit-msg'>The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:

    Double lock:
    1. spin_lock_irqsave(pch-&gt;lock, flags) at pl330_free_chan_resources:2236;
    2. call to function `pl330_release_channel' immediately after;
    3. call to function `dma_pl330_rqcb' in line 1753;
    4. spin_lock_irqsave(pch-&gt;lock, flags) at dma_pl330_rqcb:1505.

I have fixed it as suggested by Marek Szyprowski.

First, I have replaced `pch-&gt;lock' with `pl330-&gt;lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.

NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch-&gt;work_list' under lock `pl330-&gt;lock',
whereas in the rest of the code `pch-&gt;work_list' is protected by
`pch-&gt;lock'. I don't know if this may cause race conditions. Similarly
`pch-&gt;cyclic' is written by `pl330_alloc_chan_resources' under
`pl330-&gt;lock' but read by `pl330_tx_submit' under `pch-&gt;lock'.

Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.

Signed-off-by: Iago Abal &lt;mail@iagoabal.eu&gt;
Reviewed-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>Diffstat</a> (limited to 'sound/soc/fsl/imx-pcm-fiq.c')</div><table summary='diffstat' class='diffstat'>