*参照元 [#f5811402] #backlinks *説明 [#we1b9794] -パス: [[linux-4.4.1/sound/core/pcm_lib.c]] -FIXME: これは何? --説明 **引数 [#f9dd45c8] -struct snd_pcm_substream *substream -- --[[linux-4.4.1/snd_pcm_substream]] -unsigned int hwoff -- -unsigned long data -- -unsigned int off -- -snd_pcm_uframes_t frames -- --[[linux-4.4.1/snd_pcm_uframes_t]] **返り値 [#fe568f2a] -int -- **参考 [#wfc9e73a] *実装 [#b941379c] static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream, unsigned int hwoff, unsigned long data, unsigned int off, snd_pcm_uframes_t frames) { struct snd_pcm_runtime *runtime = substream->runtime; int err; char __user *buf = (char __user *) data + frames_to_bytes(runtime, off); - --[[linux-4.4.1/snd_pcm_runtime]] --[[linux-4.4.1/frames_to_bytes()]] if (substream->ops->copy) { - --substream->ops は const struct snd_pcm_ops * 型 --[[linux-4.4.1/snd_pcm_ops]] if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0) return err; } else { char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff); if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames))) return -EFAULT; - --[[linux-4.4.1/copy_from_user()]] } return 0; } *コメント [#h9b4a660]