mmc: host: sdhci: Implement the request_atomic() API

Implement the request_atomic() ops for the sdhci driver to process
one request in the atomic context if the card is nonremovable.

Moreover, we should return BUSY flag if controller has not released
the inhibit bits to allow HSQ trying to send request again in non-atomic
context.

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/9ed34afa9fb42e0c234065cac5401d7826942b55.1586744073.git.baolin.wang7@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 153c5fda0645..6cc72177f853 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2144,6 +2144,40 @@ out_finish:
 }
 EXPORT_SYMBOL_GPL(sdhci_request);
 
+int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct mmc_command *cmd;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	if (sdhci_present_error(host, mrq->cmd, true)) {
+		sdhci_finish_mrq(host, mrq);
+		goto out_finish;
+	}
+
+	cmd = sdhci_manual_cmd23(host, mrq) ? mrq->sbc : mrq->cmd;
+
+	/*
+	 * The HSQ may send a command in interrupt context without polling
+	 * the busy signaling, which means we should return BUSY if controller
+	 * has not released inhibit bits to allow HSQ trying to send request
+	 * again in non-atomic context. So we should not finish this request
+	 * here.
+	 */
+	if (!sdhci_send_command(host, cmd))
+		ret = -EBUSY;
+	else
+		sdhci_led_activate(host);
+
+out_finish:
+	spin_unlock_irqrestore(&host->lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sdhci_request_atomic);
+
 void sdhci_set_bus_width(struct sdhci_host *host, int width)
 {
 	u8 ctrl;