[PATCH] ASoC: cs48l32: Fix a signedness bug in cs48l32_hw_params()

[Harshit Mogalapalli]

There is a type promotion that can happen when freq(u32) variable is
comapared with sclk_target(integer), when sclk_target is a negative
value it promotes to a large postive integer which might not be a
problem in this particular case as the condition evaluates to false
when that happens, but bail out early when sclk_target has negative
error codes.

	cs48l32_sclk_rates[i].freq >= sclk_target

Fix this by adding a negative error check when
snd_soc_tdm_params_to_bclk() fails

Fixes: e2bcbf99d045 ("ASoC: cs48l32: Add driver for Cirrus Logic CS48L32 audio DSP")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
---
This is found using static analysis with Smatch, only compile tested.
---
 sound/soc/codecs/cs48l32.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sound/soc/codecs/cs48l32.c b/sound/soc/codecs/cs48l32.c
index 90a795230d27..9bdd48aab42a 100644
--- a/sound/soc/codecs/cs48l32.c
+++ b/sound/soc/codecs/cs48l32.c
@@ -2162,6 +2162,10 @@ static int cs48l32_hw_params(struct snd_pcm_substream *substream,
 		n_slots_multiple = 1;
 
 	sclk_target = snd_soc_tdm_params_to_bclk(params, slotw, n_slots, n_slots_multiple);
+	if (sclk_target < 0) {
+		cs48l32_asp_err(dai, "Invalid parameters\n");
+		return sclk_target;
+	}
 
 	for (i = 0; i < ARRAY_SIZE(cs48l32_sclk_rates); i++) {
 		if ((cs48l32_sclk_rates[i].freq >= sclk_target) &&
-- 
2.39.3