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@xxxxxxxxxxx>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@xxxxxxxxx>
---
There is some risk associated with this patch: it removes unconditional
(attempt of) controller reset from the tmio_mmc_host_resume() function.
AFAICS, this shouldn't have any negative effects. There _should_ always be
a powering-up .set_ios() call after a resume. However, if anyone sees any
(potential) problems with it, please, let me know.
drivers/mmc/host/tmio_mmc.h | 1 +
drivers/mmc/host/tmio_mmc_pio.c | 6 +++++-
2 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index d857f5c..759d8f4 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 f508ecb..435cc4d 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);
--
1.7.2.5
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