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

From: Ulf Hansson
Date: Fri Oct 05 2018 - 09:47:57 EST


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.

> + 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.

> +
> +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.

[...]

Otherwise, this looks good to me now.

Kind regards
Uffe