[alsa-devel] ASoC: atmel-pcm-dma: Leaking memory in atmel_pcm_hw_params

Hi,

The dmaengine based pcm driver for atmel calls snd_dmaengine_pcm_open from it's hw_params callback. There is nothing preventing an application calling hw_params more than once. snd_dmaengine_pcm_open allocates a new prtd struct each time it gets called. So in case hw_params is called multiple times we leak memory here.

Is there any specific reason why snd_dmaengine_pcm_open() needs to be called from the hw_params callback and why it can't be called from the open callback? The filter function depends on the data returned by snd_soc_dai_get_dma_data(), but as far as I can see the DAI driver calls snd_soc_dai_set_dma_data() from its startup() callback, so the data is available in the PCM drivers open callback.

- Lars