On Fri, Dec 4, 2020 at 9:57 AM Tzung-Bi Shih <tzungbi@xxxxxxxxxx> wrote: > > On Fri, Dec 4, 2020 at 4:36 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > diff --git a/sound/soc/codecs/cros_ec_codec.c b/sound/soc/codecs/cros_ec_codec.c > > index 58894bf47514..6ec673573c70 100644 > > --- a/sound/soc/codecs/cros_ec_codec.c > > +++ b/sound/soc/codecs/cros_ec_codec.c > > @@ -348,7 +348,7 @@ static int i2s_rx_event(struct snd_soc_dapm_widget *w, > > } > > > > return send_ec_host_command(priv->ec_device, EC_CMD_EC_CODEC_I2S_RX, > > - (uint8_t *)&p, sizeof(p), NULL, 0); > > + &p.cmd, sizeof(p.cmd), NULL, 0); > > } > > I would prefer your v1. > > Reasons: > 1. The change is not just kernel related. > There is a EC (embedded controller) firmware to collaborate with the > code. The firmware doesn't know the kernel only copies the first byte > of the packet (at least for now). See > https://chromium.googlesource.com/chromiumos/platform/ec/+/refs/heads/master/common/audio_codec_i2s_rx.c#120. > > 2. We don't copy partial packets in a EC host command. > IMHO, it is also not a big deal if copying a few unused bytes in the packet. Ok, so if the EC does access the uninitialized data, then it is indeed better to initialize it to zero as I first thought. Arnd
