[PATCH v2] ALSA: hda/realtek: add missing error checks for COEF index reads in alc269

[songxiebing]

From: Bob Song <songxiebing@xxxxxxxxxx>

alc_read_coef_idx() and alc_read_coefex_idx() can return -1 on error
via snd_hda_codec_read(). Several codec initialization and shutdown
functions save these return values and later write them back to
hardware registers without checking for errors, potentially corrupting
COEF register state on a read failure.

Add error checks in:
- alc282_init() and alc282_shutup(): check coef78 before write-back
- alc285_hp_init(): check coef38/coef0d/coef36 before update, check
  val before write-back, and break polling loop on error
- alc294_hp_init(): break polling loop on read error

Signed-off-by: Bob Song <songxiebing@xxxxxxxxxx>
---
v2:
 - Separate processing of return values from reading COEF and
null pointer detection for device.
---
 sound/hda/codecs/realtek/alc269.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/sound/hda/codecs/realtek/alc269.c b/sound/hda/codecs/realtek/alc269.c
index 379e1458f4ac..4645793b64ac 100644
--- a/sound/hda/codecs/realtek/alc269.c
+++ b/sound/hda/codecs/realtek/alc269.c
@@ -296,7 +296,8 @@ static void alc282_init(struct hda_codec *codec)
 		msleep(100);
 
 	/* Headphone capless set to normal mode */
-	alc_write_coef_idx(codec, 0x78, coef78);
+	if (coef78 != -1)
+		alc_write_coef_idx(codec, 0x78, coef78);
 }
 
 static void alc282_shutup(struct hda_codec *codec)
@@ -333,7 +334,8 @@ static void alc282_shutup(struct hda_codec *codec)
 
 	alc_auto_setup_eapd(codec, false);
 	alc_shutup_pins(codec);
-	alc_write_coef_idx(codec, 0x78, coef78);
+	if (coef78 != -1)
+		alc_write_coef_idx(codec, 0x78, coef78);
 }
 
 static const struct coef_fw alc283_coefs[] = {
@@ -585,15 +587,19 @@ static void alc285_hp_init(struct hda_codec *codec)
 
 	alc_write_coefex_idx(codec, 0x58, 0x00, 0xf888); /* HP depop procedure start */
 	val = alc_read_coefex_idx(codec, 0x58, 0x00);
-	for (i = 0; i < 20 && val & 0x8000; i++) {
+	for (i = 0; i < 20 && val != -1 && val & 0x8000; i++) {
 		msleep(50);
 		val = alc_read_coefex_idx(codec, 0x58, 0x00);
 	} /* Wait for depop procedure finish  */
 
-	alc_write_coefex_idx(codec, 0x58, 0x00, val); /* write back the result */
-	alc_update_coef_idx(codec, 0x38, 1<<4, coef38);
-	alc_update_coef_idx(codec, 0x0d, 0x110, coef0d);
-	alc_update_coef_idx(codec, 0x36, 3<<13, coef36);
+	if (val != -1)
+		alc_write_coefex_idx(codec, 0x58, 0x00, val); /* write back the result */
+	if (coef38 != -1)
+		alc_update_coef_idx(codec, 0x38, 1<<4, coef38);
+	if (coef0d != -1)
+		alc_update_coef_idx(codec, 0x0d, 0x110, coef0d);
+	if (coef36 != -1)
+		alc_update_coef_idx(codec, 0x36, 3<<13, coef36);
 
 	msleep(50);
 	alc_update_coef_idx(codec, 0x4a, 1<<15, 0);
@@ -858,7 +864,7 @@ static void alc294_hp_init(struct hda_codec *codec)
 
 	/* Wait for depop procedure finish  */
 	val = alc_read_coefex_idx(codec, 0x58, 0x01);
-	for (i = 0; i < 20 && val & 0x0080; i++) {
+	for (i = 0; i < 20 && val != -1 && val & 0x0080; i++) {
 		msleep(50);
 		val = alc_read_coefex_idx(codec, 0x58, 0x01);
 	}
-- 
2.25.1