On Wed, 4 Mar 2020 at 08:42, Baolin Wang <baolin.wang7@xxxxxxxxx> wrote:
>
> The SD host controller can process one request in the atomic context if
> the card is nonremovable, which means we can submit next request in the
> irq hard handler when using the MMC software queue to reduce the latency.
> Thus this patch adds a new API request_atomic() for the host controller
> and implement it for the SD host controller.
>
> Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Signed-off-by: Baolin Wang <baolin.wang7@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++--------
> drivers/mmc/host/sdhci.h | 1 +
> include/linux/mmc/host.h | 3 +++
> 3 files changed, 23 insertions(+), 8 deletions(-)
I think the code split of the changes in the series can be improved a
bit, so I suggest you move the code around in the series to reach
this:
1. A patch that adds the new host ops callback, combined with the
change you have in patch3.
2. The sdhci core specific changes, from $subject patch.
3. The sdhci-sprd changes, as in patch2.
Other than that, I think the code looks good to me, besides a minor
comment on patch2, see separate reply.
Kind regards
Uffe
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 9c37451..4febbcb 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2016,17 +2016,12 @@ void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> * *
> \*****************************************************************************/
>
> -void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> +static void sdhci_start_request(struct mmc_host *mmc, struct mmc_request *mrq,
> + int present)
> {
> - struct sdhci_host *host;
> - int present;
> + struct sdhci_host *host = mmc_priv(mmc);
> unsigned long flags;
>
> - host = mmc_priv(mmc);
> -
> - /* Firstly check card presence */
> - present = mmc->ops->get_cd(mmc);
> -
> spin_lock_irqsave(&host->lock, flags);
>
> sdhci_led_activate(host);
> @@ -2043,6 +2038,22 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>
> spin_unlock_irqrestore(&host->lock, flags);
> }
> +
> +void sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq)
> +{
> + sdhci_start_request(mmc, mrq, 1);
> +}
> +EXPORT_SYMBOL_GPL(sdhci_request_atomic);
> +
> +void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> +{
> + int present;
> +
> + /* Firstly check card presence */
> + present = mmc->ops->get_cd(mmc);
> +
> + sdhci_start_request(mmc, mrq, present);
> +}
> EXPORT_SYMBOL_GPL(sdhci_request);
>
> void sdhci_set_bus_width(struct sdhci_host *host, int width)
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index cac2d97..5507a73 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -775,6 +775,7 @@ void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> unsigned short vdd);
> void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq);
> +void sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
> void sdhci_set_bus_width(struct sdhci_host *host, int width);
> void sdhci_reset(struct sdhci_host *host, u8 mask);
> void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 562ed06..db5e59c 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -92,6 +92,9 @@ struct mmc_host_ops {
> int err);
> void (*pre_req)(struct mmc_host *host, struct mmc_request *req);
> void (*request)(struct mmc_host *host, struct mmc_request *req);
> + /* Submit one request to host in atomic context. */
> + void (*request_atomic)(struct mmc_host *host,
> + struct mmc_request *req);
>
> /*
> * Avoid calling the next three functions too often or in a "fast
> --
> 1.9.1
>
