[PATCH 2/3] mmc: host: sdhci-sprd: Implement the request_atomic() API

From: Baolin Wang
Date: Thu Dec 26 2019 - 06:31:10 EST


Implement the request_atomic() API for nonremovable cards, that means
we can submit next request in the irq hard handler context to reduce
latency.

Signed-off-by: Baolin Wang <baolin.wang7@xxxxxxxxx>
---
drivers/mmc/host/sdhci-sprd.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
index d346223..ae9acb8 100644
--- a/drivers/mmc/host/sdhci-sprd.c
+++ b/drivers/mmc/host/sdhci-sprd.c
@@ -426,6 +426,27 @@ static void sdhci_sprd_request(struct mmc_host *mmc, struct mmc_request *mrq)
sdhci_request(mmc, mrq);
}

+static void sdhci_sprd_request_atomic(struct mmc_host *mmc,
+ struct mmc_request *mrq)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
+
+ host->flags |= sprd_host->flags & SDHCI_AUTO_CMD23;
+
+ /*
+ * From version 4.10 onward, ARGUMENT2 register is also as 32-bit
+ * block count register which doesn't support stuff bits of
+ * CMD23 argument on Spreadtrum's sd host controller.
+ */
+ if (host->version >= SDHCI_SPEC_410 &&
+ mrq->sbc && (mrq->sbc->arg & SDHCI_SPRD_ARG2_STUFF) &&
+ (host->flags & SDHCI_AUTO_CMD23))
+ host->flags &= ~SDHCI_AUTO_CMD23;
+
+ sdhci_request_atomic(mmc, mrq);
+}
+
static int sdhci_sprd_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct sdhci_host *host = mmc_priv(mmc);
@@ -561,6 +582,11 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
if (ret)
goto pltfm_free;

+ if (!mmc_card_is_removable(host->mmc))
+ host->mmc_host_ops.request_atomic = sdhci_sprd_request_atomic;
+ else
+ host->always_defer_done = true;
+
sprd_host = TO_SPRD_HOST(host);
sdhci_sprd_phy_param_parse(sprd_host, pdev->dev.of_node);

@@ -654,8 +680,6 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
if (ret)
goto err_cleanup_host;

- host->always_defer_done = true;
-
ret = __sdhci_add_host(host);
if (ret)
goto err_cleanup_host;
--
1.7.9.5