Re-tuning is not possible when switched to the RPMB
partition. However re-tuning should not be needed
if re-tuning is done immediately before switching,
a small set of operations is done, and then we
immediately switch back to the main partition.
To ensure that re-tuning can't be done for a short
while, add a facility to "pause" re-tuning.
The existing facility to hold / release re-tuning
is used but it also flags re-tuning as needed to cause
re-tuning before the next command (which will be the
switch to RPMB).
We also need to "unpause" in the recovery path, which
is catered for by adding it to mmc_retune_disable().
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
Changes in V3:
Added:
EXPORT_SYMBOL(mmc_retune_pause);
EXPORT_SYMBOL(mmc_retune_unpause);
Changes in V2:
New approach entirely
drivers/mmc/core/host.c | 24 ++++++++++++++++++++++++
include/linux/mmc/host.h | 4 ++++
2 files changed, 28 insertions(+)
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index e0a3ee16c0d3..1be42fab1a30 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -68,8 +68,32 @@ void mmc_retune_enable(struct mmc_host *host)
jiffies + host->retune_period * HZ);
}
+/*
+ * Pause re-tuning for a small set of operations. The pause begins after the
+ * next command and after first doing re-tuning.
+ */
+void mmc_retune_pause(struct mmc_host *host)
+{
+ if (!host->retune_paused) {
+ host->retune_paused = 1;
+ mmc_retune_needed(host);
+ mmc_retune_hold(host);
+ }
+}
+EXPORT_SYMBOL(mmc_retune_pause);
+
+void mmc_retune_unpause(struct mmc_host *host)
+{
+ if (host->retune_paused) {
+ host->retune_paused = 0;
+ mmc_retune_release(host);
+ }
+}
+EXPORT_SYMBOL(mmc_retune_unpause);
+
void mmc_retune_disable(struct mmc_host *host)
{
+ mmc_retune_unpause(host);
host->can_retune = 0;
del_timer_sync(&host->retune_timer);
host->retune_now = 0;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 85800b48241f..45cde8cd39f2 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -329,6 +329,7 @@ struct mmc_host {
unsigned int can_retune:1; /* re-tuning can be used */
unsigned int doing_retune:1; /* re-tuning in progress */
unsigned int retune_now:1; /* do re-tuning at next req */
+ unsigned int retune_paused:1; /* re-tuning is temporarily disabled */
int rescan_disable; /* disable card detection */
int rescan_entered; /* used with nonremovable devices */
@@ -526,4 +527,7 @@ static inline void mmc_retune_recheck(struct mmc_host *host)
host->retune_now = 1;
}
+void mmc_retune_pause(struct mmc_host *host);
+void mmc_retune_unpause(struct mmc_host *host);
+
#endif /* LINUX_MMC_HOST_H */
--
1.9.1
--
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