mmc: core: Add MMC_CAP_RUNTIME_RESUME to resume at runtime_resume
In some environments it is to prefer to postpone the resume of the card
device until runtime_resume is being carried out, since it will mean a
signficant decrease of the total system resume time.
The reason of the decreased resume time is simply because of the actual
re-initalization of the card, which typically takes hundreds of
milliseconds, is performed outside the resume sequence and wont thus
affect it.
For removable card, the detect work tries to re-detect the card to make
sure it is still present, as a part of that sequence the card will also
be runtime_resumed and thus also fully resumed.
For a non-removable card, typically a mmc blk request will trigger a
runtime_resume and thus fully resume the card. This also means the
first request will likely suffer from an inital latency since the
re-initialization of the card needs to be performed.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f18669e..99f5709 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -254,6 +254,7 @@
#define MMC_CAP_UHS_SDR50 (1 << 17) /* Host supports UHS SDR50 mode */
#define MMC_CAP_UHS_SDR104 (1 << 18) /* Host supports UHS SDR104 mode */
#define MMC_CAP_UHS_DDR50 (1 << 19) /* Host supports UHS DDR50 mode */
+#define MMC_CAP_RUNTIME_RESUME (1 << 20) /* Resume at runtime_resume. */
#define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
#define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
#define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */