[alsa-devel] ASoC: davinci-mcasp: Set rule constraints if implicit BCLK divider is used

[Dan Carpenter]

Hello Jyri Sarha,

The patch a75a053f1eef: "ASoC: davinci-mcasp: Set rule constraints if
implicit BCLK divider is used" from Mar 20, 2015, leads to the
following Smatch warning:

	sound/soc/davinci/davinci-mcasp.c:1152 davinci_mcasp_startup()
	error: buffer overflow 'mcasp->ruledata' 2 <= 2

sound/soc/davinci/davinci-mcasp.c
  1138  
  1139          /*
  1140           * Limit the maximum allowed channels for the first stream:
  1141           * number of serializers for the direction * tdm slots per serializer
  1142           */
  1143          if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  1144                  dir = TX_MODE;
  1145          else
  1146                  dir = RX_MODE;

dir is either 1 or 2.

  1147  
  1148          for (i = 0; i < mcasp->num_serializer; i++) {
  1149                  if (mcasp->serial_dir[i] == dir)
  1150                          max_channels++;
  1151          }
  1152          mcasp->ruledata[dir].serializers = max_channels;
                       ^^^^^^^^^^^^^
->ruledata[] has only two elements so ->ruledata[2] is beyond the end of
the array.

  1153          max_channels *= mcasp->tdm_slots;

regards,
dan carpenter