Re: [RESEND v13 04/10] ASoC: qcom: Add helper function to get dma control and lpaif handle

[Srinivasa Rao Mandadapu (Temp)]

On 2/18/2022 1:11 AM, Stephen Boyd wrote:
Thanks for Your time Stephen!!!
> Quoting Srinivasa Rao Mandadapu (2022-02-15 21:11:29)
> > On 2/15/2022 6:40 AM, Stephen Boyd wrote:
> > Thanks for your time Stephen!!!
> > > Quoting Srinivasa Rao Mandadapu (2022-02-14 06:58:22)
> > > > Add support function to get dma control and lpaif handle to avoid
> > > > repeated code in platform driver
> > > >
> > > > Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@xxxxxxxxxxx>
> > > > Co-developed-by: Venkata Prasad Potturu <quic_potturu@xxxxxxxxxxx>
> > > > Signed-off-by: Venkata Prasad Potturu <quic_potturu@xxxxxxxxxxx>
> > > > Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > > > ---
> > > >    sound/soc/qcom/lpass-platform.c | 113 +++++++++++++++++++++++-----------------
> > > >    1 file changed, 66 insertions(+), 47 deletions(-)
> > > >
> > > > diff --git a/sound/soc/qcom/lpass-platform.c b/sound/soc/qcom/lpass-platform.c
> > > > index a44162c..5d77240 100644
> > > > --- a/sound/soc/qcom/lpass-platform.c
> > > > +++ b/sound/soc/qcom/lpass-platform.c
> > > > @@ -177,6 +177,49 @@ static int lpass_platform_pcmops_close(struct snd_soc_component *component,
> > > >           return 0;
> > > >    }
> > > >
> > > > +static void __lpass_get_lpaif_handle(struct snd_pcm_substream *substream,
> > > const?
> > Okay. will add const to substream pointer.
> > > > +                                    struct snd_soc_component *component,
> > > const?
> > Here const is giving compilation errors in below code.
> Ok
>
> > > > +                       l_id = pcm_data->dma_ch;
> > > > +                       l_dmactl = drvdata->rd_dmactl;
> > > > +               } else {
> > > > +                       l_dmactl = drvdata->wr_dmactl;
> > > > +                       l_id = pcm_data->dma_ch - v->wrdma_channel_start;
> > > > +               }
> > > > +               l_map = drvdata->lpaif_map;
> > > > +               break;
> > > > +       case LPASS_DP_RX:
> > > > +               l_id = pcm_data->dma_ch;
> > > > +               l_dmactl = drvdata->hdmi_rd_dmactl;
> > > > +               l_map = drvdata->hdmiif_map;
> > > > +               break;
> > > > +       default:
> > > > +               break;
> > > > +       }
> > > > +       if (dmactl)
> > > > +               *dmactl = l_dmactl;
> > > > +       if (id)
> > > > +               *id = l_id;
> > > > +       if (map)
> > > > +               *map = l_map;
> > > Why not 'return 0' here and return -EINVAL in the default case above? Then
> > > we can skip the checks for !map or !dmactl below and simply bail out if
> > > it failed with an error value.
> > Here the check is for input params. some users call for only damctl or
> > only map.
> Yes the check is to make sure there's a pointer to store the value into.
> I get that. The users are all internal to this driver though because
> the function is static. If the function returned an error because it
> couldn't find something then we wouldn't have to test the resulting
> pointers for success, instead we could check for a return value.
> Similarly, it may be clearer to have a single get for each item and then
> return a pointer from the function vs. passing it in to extract
> something. It may duplicate some code but otherwise the code would be
> clearer because we're getting one thing and can pass an error value
> through the pointer with PTR_ERR().

Okay. Agreed. But in initial review comments, asked to make common 
function for code readability,

and to avoid duplicate code.

Anyway will change accordingly and re post it.