From be588ca11dcf2c0cca1a02c4c0a179f87eddc2ec Mon Sep 17 00:00:00 2001
From: Yuan Lin <yualin@google.com>
Date: Wed, 17 Aug 2016 10:03:11 -0700
Subject: [PATCH] ASoC: check for null function pointer for dummy device
read/write
Adding check for null function pointer for dummy sound driver
read/write to prevent kernel panic.
Bug: 28838221
Change-Id: I32548a7e37869a17a5f88c646ddbfb8243cadcc0
Signed-off-by: Yuan Lin <yualin@google.com>
---
sound/soc/soc-core.c | 36 ++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index b6d808c06791..abcb4719632f 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -2103,13 +2103,17 @@ unsigned int snd_soc_read(struct snd_soc_codec *codec, unsigned int reg)
{
unsigned int ret;
- if (unlikely(!snd_card_is_online_state(codec->card->snd_card))) {
- dev_err(codec->dev, "read 0x%02x while offline\n", reg);
- return -ENODEV;
- }
- ret = codec->read(codec, reg);
- dev_dbg(codec->dev, "read %x => %x\n", reg, ret);
- trace_snd_soc_reg_read(codec, reg, ret);
+ if (codec->read) {
+ if (unlikely(!snd_card_is_online_state(codec->card->snd_card))) {
+ dev_err(codec->dev, "read 0x%02x while offline\n", reg);
+ return -ENODEV;
+ }
+ ret = codec->read(codec, reg);
+ dev_dbg(codec->dev, "read %x => %x\n", reg, ret);
+ trace_snd_soc_reg_read(codec, reg, ret);
+ }
+ else
+ ret = -EIO;
return ret;
}
@@ -2118,13 +2122,17 @@ EXPORT_SYMBOL_GPL(snd_soc_read);
unsigned int snd_soc_write(struct snd_soc_codec *codec,
unsigned int reg, unsigned int val)
{
- if (unlikely(!snd_card_is_online_state(codec->card->snd_card))) {
- dev_err(codec->dev, "write 0x%02x while offline\n", reg);
- return -ENODEV;
- }
- dev_dbg(codec->dev, "write %x = %x\n", reg, val);
- trace_snd_soc_reg_write(codec, reg, val);
- return codec->write(codec, reg, val);
+ if (codec->write) {
+ if (unlikely(!snd_card_is_online_state(codec->card->snd_card))) {
+ dev_err(codec->dev, "write 0x%02x while offline\n", reg);
+ return -ENODEV;
+ }
+ dev_dbg(codec->dev, "write %x = %x\n", reg, val);
+ trace_snd_soc_reg_write(codec, reg, val);
+ return codec->write(codec, reg, val);
+ }
+ else
+ return -EIO;
}
EXPORT_SYMBOL_GPL(snd_soc_write);
--
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