Re: [PATCH V5 02/24] mmc: mmci: create common mmci_dma_setup/release

[Ludovic BARRE <ludovic.barre@xxxxxx>]

On 10/05/2018 03:47 PM, Ulf Hansson wrote:
> On 5 October 2018 at 15:22, Ludovic Barre <ludovic.Barre@xxxxxx> wrote:
> > From: Ludovic Barre <ludovic.barre@xxxxxx>
> >
> > This patch creates a common mmci_dma_setup/release which calls
> > dma_setup/release callbacks of mmci_host_ops and manages
> > common features like use_dma... If there is a fallbacks to
> > pio mode, dma functions must check use_dma.
> >
> > error management:
> > -mmci_dmae_setup fail if Tx and Rx dma channels are not defined
> > -qcom_dma_setup fail if one of both dma channels is not defined,
> >   Qcom has no specific resource to release, just mmci dmae resource.
>
> Makes perfect sense!
>
> [...]
>
> > +void mmci_dma_setup(struct mmci_host *host)
> > +{
> > +       if (!host->ops || !host->ops->dma_setup)
> > +               return;
> > +
> > +       if (host->ops->dma_setup(host)) {
> > +               mmci_dma_release(host);
>
> Please remove this and let the variants clean up themselves. That
> makes it more straight forward.

This common call was not such a good idea.
Ok, I will back on first idea.

> > +               return;
> > +       }
> > +
> > +       host->use_dma = true;
> > +}
> > +
>
> [...]
>
> > diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
> > index 01e6c6b..9b0a960 100644
> > --- a/drivers/mmc/host/mmci.h
> > +++ b/drivers/mmc/host/mmci.h
> > @@ -273,7 +273,8 @@ struct variant_data {
> >
> >   /* mmci variant callbacks */
> >   struct mmci_host_ops {
> > -       void (*dma_setup)(struct mmci_host *host);
> > +       int (*dma_setup)(struct mmci_host *host);
> > +       void (*dma_release)(struct mmci_host *host);
> >   };
> >
> >   struct mmci_host_next {
> > @@ -323,6 +324,7 @@ struct mmci_host {
> >          unsigned int            size;
> >          int (*get_rx_fifocnt)(struct mmci_host *h, u32 status, int remain);
> >
> > +       u8                      use_dma:1;
> >   #ifdef CONFIG_DMA_ENGINE
> >          /* DMA stuff */
> >          struct dma_chan         *dma_current;
> > @@ -336,3 +338,14 @@ struct mmci_host {
> >   #endif
> >   };
> >
> > +#ifdef CONFIG_DMA_ENGINE
> > +void mmci_variant_init(struct mmci_host *host);
> > +#else
> > +static inline void mmci_variant_init(struct mmci_host *host)
> > +{
> > +}
> > +#endif
>
> This can be kept in mmci.c instead.

OK

> > +
> > +int mmci_dmae_setup(struct mmci_host *host);
> > +void mmci_dmae_release(struct mmci_host *host);
> > +
> > diff --git a/drivers/mmc/host/mmci_qcom_dml.c b/drivers/mmc/host/mmci_qcom_dml.c
> > index be3fab5..aa070a9 100644
> > --- a/drivers/mmc/host/mmci_qcom_dml.c
> > +++ b/drivers/mmc/host/mmci_qcom_dml.c
> > @@ -119,19 +119,22 @@ static int of_get_dml_pipe_index(struct device_node *np, const char *name)
> >   }
> >
> >   /* Initialize the dml hardware connected to SD Card controller */
> > -static void qcom_dma_setup(struct mmci_host *host)
> > +static int qcom_dma_setup(struct mmci_host *host)
> >   {
> >          u32 config;
> >          void __iomem *base;
> >          int consumer_id, producer_id;
> >          struct device_node *np = host->mmc->parent->of_node;
> >
> > +       if (mmci_dmae_setup(host))
> > +               return -EINVAL;
> > +
> >          consumer_id = of_get_dml_pipe_index(np, "tx");
> >          producer_id = of_get_dml_pipe_index(np, "rx");
> >
> >          if (producer_id < 0 || consumer_id < 0) {
> >                  host->variant->qcom_dml = false;
> > -               return;
> > +               return -EINVAL;
>
> This relies on error handling to be done by mmci_dma_setup(), which as
> stated, feels a bit wrong.
>
> I would rather just call mmci_dmae_realease() here, before returning -EINVAL.

OK

> [...]
>
> Otherwise, this looks good to me now.
>
> Kind regards
> Uffe