ASoC: soc-core: Support debugfs entries larger than PAGE_SIZE bytes (13fd179f) · Commits · 戴 / test

sound/soc/soc-core.c

+73 −37

Original line number	Diff line number	Diff line
		@@ -87,15 +87,56 @@ static int min_bytes_needed(unsigned long val)
		return c;
		}

		/* fill buf which is 'len' bytes with a formatted
		* string of the form 'reg: value\n' */
		static int format_register_str(struct snd_soc_codec *codec,
		unsigned int reg, char *buf, size_t len)
		{
		int wordsize = codec->driver->reg_word_size * 2;
		int regsize = min_bytes_needed(codec->driver->reg_cache_size) * 2;
		int ret;
		char tmpbuf[len + 1];
		char regbuf[regsize + 1];

		/* since tmpbuf is allocated on the stack, warn the callers if they
		* try to abuse this function */
		WARN_ON(len > 63);

		/* +2 for ': ' and + 1 for '\n' */
		if (wordsize + regsize + 2 + 1 != len)
		return -EINVAL;

		ret = snd_soc_read(codec , reg);
		if (ret < 0) {
		memset(regbuf, 'X', regsize);
		regbuf[regsize] = '\0';
		} else {
		snprintf(regbuf, regsize + 1, "%.*x", regsize, ret);
		}

		/* prepare the buffer */
		snprintf(tmpbuf, len + 1, "%.*x: %s\n", wordsize, reg, regbuf);
		/* copy it back to the caller without the '\0' */
		memcpy(buf, tmpbuf, len);

		return 0;
		}

		/* codec register dump */
		static ssize_t soc_codec_reg_show(struct snd_soc_codec codec, char buf)
		static ssize_t soc_codec_reg_show(struct snd_soc_codec codec, char buf,
		size_t count, loff_t pos)
		{
		int ret, i, step = 1, count = 0;
		int i, step = 1;
		int wordsize, regsize;
		int len;
		size_t total = 0;
		loff_t p = 0;

		wordsize = codec->driver->reg_word_size * 2;
		regsize = min_bytes_needed(codec->driver->reg_cache_size) * 2;

		len = wordsize + regsize + 2 + 1;

		if (!codec->driver->reg_cache_size)
		return 0;

		@@ -105,51 +146,34 @@ static ssize_t soc_codec_reg_show(struct snd_soc_codec codec, char buf)
		for (i = 0; i < codec->driver->reg_cache_size; i += step) {
		if (codec->readable_register && !codec->readable_register(codec, i))
		continue;

		count += sprintf(buf + count, "%.*x: ", regsize, i);
		if (count >= PAGE_SIZE - 1)
		break;

		if (codec->driver->display_register) {
		count += codec->driver->display_register(codec, buf + count,
		PAGE_SIZE - count, i);
		} else {
		/* If the read fails it's almost certainly due to
		* the register being volatile and the device being
		* powered off.
		*/
		ret = snd_soc_read(codec, i);
		if (ret >= 0)
		count += snprintf(buf + count,
		PAGE_SIZE - count,
		"%.*x", wordsize, ret);
		else
		count += snprintf(buf + count,
		PAGE_SIZE - count,
		"<no data: %d>", ret);
		}

		if (count >= PAGE_SIZE - 1)
		break;

		count += snprintf(buf + count, PAGE_SIZE - count, "\n");
		if (count >= PAGE_SIZE - 1)
		/* only support larger than PAGE_SIZE bytes debugfs
		* entries for the default case */
		if (p >= pos) {
		if (total + len >= count - 1)
		break;
		format_register_str(codec, i, buf + total, len);
		total += len;
		}
		p += len;
		}
		}

		/* Truncate count; min() would cause a warning */
		if (count >= PAGE_SIZE)
		count = PAGE_SIZE - 1;
		total = min(total, count - 1);

		return count;
		return total;
		}

		static ssize_t codec_reg_show(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct snd_soc_pcm_runtime *rtd =
		container_of(dev, struct snd_soc_pcm_runtime, dev);

		return soc_codec_reg_show(rtd->codec, buf);
		return soc_codec_reg_show(rtd->codec, buf, PAGE_SIZE, 0);
		}

		static DEVICE_ATTR(codec_reg, 0444, codec_reg_show, NULL);
		@@ -192,12 +216,24 @@ static ssize_t codec_reg_read_file(struct file file, char __user user_buf,
		{
		ssize_t ret;
		struct snd_soc_codec *codec = file->private_data;
		char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
		char *buf;

		if (*ppos < 0 \|\| !count)
		return -EINVAL;

		buf = kmalloc(count, GFP_KERNEL);
		if (!buf)
		return -ENOMEM;
		ret = soc_codec_reg_show(codec, buf);
		if (ret >= 0)
		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);

		ret = soc_codec_reg_show(codec, buf, count, *ppos);
		if (ret >= 0) {
		if (copy_to_user(user_buf, buf, ret)) {
		kfree(buf);
		return -EFAULT;
		}
		*ppos += ret;
		}

		kfree(buf);
		return ret;
		}

Admin message