[alsa-devel] Applied "ASoC: max98373: check for device node before parsing" to the asoc tree

[Mark Brown]

The patch

   ASoC: max98373: check for device node before parsing

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.4

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 4bb41984bf2f4cb8ed6ec1579d317790bd941788 Mon Sep 17 00:00:00 2001
From: Sathyanarayana Nujella <sathyanarayana.nujella at intel.com>
Date: Sat, 28 Sep 2019 13:22:30 -0700
Subject: [PATCH] ASoC: max98373: check for device node before parsing

Below Oops is caused in a system which uses ACPI instead of device node:

of_get_named_gpiod_flags: can't parse 'maxim,reset-gpio' property of node '(null)[0]'
BUG: kernel NULL pointer dereference, address: 0000000000000010

This patch avoids NULL pointer deferencing by adding a check before parsing
and initializes to make reset-gpio pin as invalid.

Signed-off-by: Sathyanarayana Nujella <sathyanarayana.nujella at intel.com>
Signed-off-by: Jairaj Arava <jairaj.arava at intel.com>
Link: https://lore.kernel.org/r/1569702150-11976-1-git-send-email-sathyanarayana.nujella@intel.com
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/codecs/max98373.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/sound/soc/codecs/max98373.c b/sound/soc/codecs/max98373.c
index e609abcf3220..eb709d528259 100644
--- a/sound/soc/codecs/max98373.c
+++ b/sound/soc/codecs/max98373.c
@@ -901,16 +901,20 @@ static void max98373_slot_config(struct i2c_client *i2c,
 		max98373->i_slot = value & 0xF;
 	else
 		max98373->i_slot = 1;
-
-	max98373->reset_gpio = of_get_named_gpio(dev->of_node,
+	if (dev->of_node) {
+		max98373->reset_gpio = of_get_named_gpio(dev->of_node,
 						"maxim,reset-gpio", 0);
-	if (!gpio_is_valid(max98373->reset_gpio)) {
-		dev_err(dev, "Looking up %s property in node %s failed %d\n",
-			"maxim,reset-gpio", dev->of_node->full_name,
-			max98373->reset_gpio);
+		if (!gpio_is_valid(max98373->reset_gpio)) {
+			dev_err(dev, "Looking up %s property in node %s failed %d\n",
+				"maxim,reset-gpio", dev->of_node->full_name,
+				max98373->reset_gpio);
+		} else {
+			dev_dbg(dev, "maxim,reset-gpio=%d",
+				max98373->reset_gpio);
+		}
 	} else {
-		dev_dbg(dev, "maxim,reset-gpio=%d",
-			max98373->reset_gpio);
+		/* this makes reset_gpio as invalid */
+		max98373->reset_gpio = -1;
 	}
 
 	if (!device_property_read_u32(dev, "maxim,spkfb-slot-no", &value))
-- 
2.20.1