mmc: tmio: postpone controller reset during resume

When resuming, the tmio_mmc_host_resume() function is run when the
controller might still be powered down. Issuing a reset command to it at
that time has no effect. This patch postpones resetting the controller
until the first powering-up .set_ios() call.
Reported-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/tmio_mmc.h

@@ -85,6 +85,7 @@ struct tmio_mmc_host {
 	unsigned long		last_req_ts;
 	struct mutex		ios_lock;	/* protect set_ios() context */
 	bool			native_hotplug;
+	bool			resuming;
 };
 
 int tmio_mmc_host_probe(struct tmio_mmc_host **host,

drivers/mmc/host/tmio_mmc_pio.c

@@ -862,6 +862,10 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		if (!host->power) {
 			tmio_mmc_clk_update(mmc);
 			pm_runtime_get_sync(dev);
+			if (host->resuming) {
+				tmio_mmc_reset(host);
+				host->resuming = false;
+			}
 		}
 		tmio_mmc_set_clock(host, ios->clock);
 		if (!host->power) {
@@ -1154,10 +1158,10 @@ int tmio_mmc_host_resume(struct device *dev)
 	struct mmc_host *mmc = dev_get_drvdata(dev);
 	struct tmio_mmc_host *host = mmc_priv(mmc);
 
-	tmio_mmc_reset(host);
 	tmio_mmc_enable_dma(host, true);
 
 	/* The MMC core will perform the complete set up */
+	host->resuming = true;
 	return mmc_resume_host(mmc);
 }
 EXPORT_SYMBOL(tmio_mmc_host_resume);