On Mon, 2022-07-25 at 10:28 +0300, Dan Carpenter wrote:

Hello Jiaxin Yu,

This is a semi-automatic email about new static checker warnings.

The patch ae92dcbee8b6: "ASoC: mediatek: mt8186: support tdm in platform driver" from May 23, 2022, leads to the following Smatch complaint:

sound/soc/mediatek/mt8186/mt8186-dai-tdm.c:424

mtk_dai_tdm_hw_params() warn: variable dereferenced before check 'tdm_priv' (see line 406)

sound/soc/mediatek/mt8186/mt8186-dai-tdm.c 405 struct mtk_afe_tdm_priv *tdm_priv = afe_priv-

...

dai_priv[tdm_id];

406 unsigned int tdm_mode = tdm_priv->tdm_mode; ^^^^^^^^^^^^^^^^^^^ Lot's of dereferences

407 unsigned int data_mode = tdm_priv->data_mode; 408 unsigned int rate = params_rate(params); 409 unsigned int channels = params_channels(params); 410 snd_pcm_format_t format = params_format(params); 411 unsigned int bit_width = 412 snd_pcm_format_physical_width(format); 413 unsigned int tdm_channels = (data_mode == TDM_DATA_ONE_PIN) ? 414 get_tdm_ch_per_sdata(tdm_mode, channels) : 2; 415 unsigned int lrck_width = 416 get_tdm_lrck_width(format, tdm_mode); 417 unsigned int tdm_con = 0; 418 bool slave_mode = tdm_priv->slave_mode; 419 bool lrck_inv = tdm_priv->lck_invert; 420 bool bck_inv = tdm_priv->bck_invert; 421 unsigned int tran_rate; 422 unsigned int tran_relatch_rate; 423 424 if (!tdm_priv) { ^^^^^^^^^ Checked too late

425 dev_err(afe->dev, "%s(), tdm_priv == NULL", __func__); 426 return -EINVAL;

regards, dan carpenter

Yes, it's a mistake. In fact, the judgment here is really unnecessary. Because when registering, if tdm_priv is NULL, registration will fail. So I will remove this code, and check other DAI drivers, then remove judgments link this.

Thanks, Jiaxin.Yu