1 files changed, 46 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0990-Fixes-a-problem-when-module-probes-before-i2c-module.patch b/target/linux/bcm27xx/patches-5.4/950-0990-Fixes-a-problem-when-module-probes-before-i2c-module.patch
new file mode 100644
index 0000000000..e9397727e9
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0990-Fixes-a-problem-when-module-probes-before-i2c-module.patch
@@ -0,0 +1,46 @@
+From bc55eb17b46668e70dfbd1a091159935d8f95eb9 Mon Sep 17 00:00:00 2001
+From: Joerg Schambacher <joerg@i2audio.com>
+Date: Fri, 16 Oct 2020 15:17:07 +0200
+Subject: [PATCH] Fixes a problem when module probes before i2c
+ module is available
+
+The driver crashed while a NULL pointer returned by i2c_get_adapter()
+has been used to access the i2c bus functions.
+The headphone probing function hb_hp_probe() now returns -EPROBE_DEFER
+in case the i2c module has not been loaded yet.
+
+Signed-off-by: Joerg Schambacher <joerg@i2audio.com>
+---
+ sound/soc/bcm/hifiberry_dacplus.c | 9 +++++++--
+ 1 file changed, 7 insertions(+), 2 deletions(-)
+
+--- a/sound/soc/bcm/hifiberry_dacplus.c
++++ b/sound/soc/bcm/hifiberry_dacplus.c
+@@ -315,12 +315,14 @@ static int hb_hp_detect(void)
+ {
+ 	struct i2c_adapter *adap = i2c_get_adapter(1);
+ 	int ret;
+-
+ 	struct i2c_client tpa_i2c_client = {
+ 		.addr = 0x60,
+ 		.adapter = adap,
+ 	};
+ 
++	if (!adap)
++		return -EPROBE_DEFER;	/* I2C module not yet available */
++
+ 	ret = i2c_smbus_read_byte(&tpa_i2c_client) >= 0;
+ 	i2c_put_adapter(adap);
+ 	return ret;
+@@ -342,7 +344,10 @@ static int snd_rpi_hifiberry_dacplus_pro
+ 	struct of_changeset ocs;
+ 
+ 	/* probe for head phone amp */
+-	if (hb_hp_detect()) {
++	ret = hb_hp_detect();
++	if (ret < 0)
++		return ret;
++	if (ret) {
+ 		card->aux_dev = hifiberry_dacplus_aux_devs;
+ 		card->num_aux_devs =
+ 				ARRAY_SIZE(hifiberry_dacplus_aux_devs);