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>

2 files changed, 6 insertions, 1 deletions

diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index d857f5c6e7d9..759d8f4f130c 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/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,
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index f508ecb5b8a7..435cc4d2520f 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/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);