[PATCH] ALSA: aoa: Handle empty codec list in i2sbus_pcm_prepare()

[Thorsten Blum]

Replace two list_for_each_entry() loops with list_first_entry_or_null()
in i2sbus_pcm_prepare().

Handle an empty codec list explicitly by returning -ENODEV, which avoids
using uninitialized 'bi.sysclock_factor' in the 32-bit code path.

Fixes: f3d9478b2ce4 ("[ALSA] snd-aoa: add snd-aoa")
Cc: sta...@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.b...@linux.dev>
---
 sound/aoa/soundbus/i2sbus/pcm.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/sound/aoa/soundbus/i2sbus/pcm.c b/sound/aoa/soundbus/i2sbus/pcm.c
index aff99003d833..65653601662d 100644
--- a/sound/aoa/soundbus/i2sbus/pcm.c
+++ b/sound/aoa/soundbus/i2sbus/pcm.c
@@ -314,7 +314,7 @@ static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, 
int in)
        int i, periodsize, nperiods;
        dma_addr_t offset;
        struct bus_info bi;
-       struct codec_info_item *cii;
+       struct codec_info_item *cii = NULL;
        int sfr = 0;            /* serial format register */
        int dws = 0;            /* data word sizes reg */
        int input_16bit;
@@ -390,13 +390,11 @@ static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, 
int in)
        case SNDRV_PCM_FORMAT_U16_BE:
                /* FIXME: if we add different bus factors we need to
                 * do more here!! */
-               bi.bus_factor = 0;
-               list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
-                       bi.bus_factor = cii->codec->bus_factor;
-                       break;
-               }
-               if (!bi.bus_factor)
+               cii = list_first_entry_or_null(&i2sdev->sound.codec_list,
+                                              struct codec_info_item, list);
+               if (!cii)
                        return -ENODEV;
+               bi.bus_factor = cii->codec->bus_factor;
                input_16bit = 1;
                break;
        case SNDRV_PCM_FORMAT_S32_BE:
@@ -410,10 +408,12 @@ static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, 
int in)
                return -EINVAL;
        }
        /* we assume all sysclocks are the same! */
-       list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
-               bi.sysclock_factor = cii->codec->sysclock_factor;
-               break;
-       }
+       if (!cii)
+               cii = list_first_entry_or_null(&i2sdev->sound.codec_list,
+                                              struct codec_info_item, list);
+       if (!cii)
+               return -ENODEV;
+       bi.sysclock_factor = cii->codec->sysclock_factor;
 
        if (clock_and_divisors(bi.sysclock_factor,
                               bi.bus_factor,