From 4730831c7d2e28c2e912b2c71066b9cf072f7625 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Wed, 12 Feb 2020 12:12:59 +0800 Subject: [PATCH] mmc: host: sdhci: Add a variable to defer to complete requests if needed When using the host software queue, it will trigger the next request in irq handler without a context switch. But the sdhci_request() can not be called in interrupt context when using host software queue for some host drivers, due to the get_cd() ops can be sleepable. But for some host drivers, such as Spreadtrum host driver, the card is nonremovable, so the get_cd() ops is not sleepable, which means we can complete the data request and trigger the next request in irq handler to remove the context switch for the Spreadtrum host driver. As suggested by Adrian, we should introduce a request_atomic() API to indicate that a request can be called in interrupt context to remove the context switch when using mmc host software queue. But this should be done in another thread to convert the users of mmc host software queue. Thus we can introduce a variable in struct sdhci_host to indicate that we will always to defer to complete requests when using the host software queue. Suggested-by: Adrian Hunter Signed-off-by: Baolin Wang Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/e693e7a29beb3c1922b333f4603ea81f43d5c5b1.1581478568.git.baolin.wang7@gmail.com Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci.c | 2 +- drivers/mmc/host/sdhci.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 9761981768f5..9c3745118e49 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -3250,7 +3250,7 @@ static inline bool sdhci_defer_done(struct sdhci_host *host, { struct mmc_data *data = mrq->data; - return host->pending_reset || + return host->pending_reset || host->always_defer_done || ((host->flags & SDHCI_REQ_USE_DMA) && data && data->host_cookie == COOKIE_MAPPED); } diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 3e95f74cd05a..cac2d97782e6 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -537,6 +537,7 @@ struct sdhci_host { bool irq_wake_enabled; /* IRQ wakeup is enabled */ bool v4_mode; /* Host Version 4 Enable */ bool use_external_dma; /* Host selects to use external DMA */ + bool always_defer_done; /* Always defer to complete requests */ struct mmc_request *mrqs_done[SDHCI_MAX_MRQS]; /* Requests done */ struct mmc_command *cmd; /* Current command */ -- 2.20.1