mmc: core: Use CMD23 for multiblock transfers when we can.
CMD23-prefixed instead of open-ended multiblock transfers
have a performance advantage on some MMC cards.
Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index de32e6a..e946bd1 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -210,6 +210,7 @@
#define MMC_CAP_MAX_CURRENT_400 (1 << 27) /* Host max current limit is 400mA */
#define MMC_CAP_MAX_CURRENT_600 (1 << 28) /* Host max current limit is 600mA */
#define MMC_CAP_MAX_CURRENT_800 (1 << 29) /* Host max current limit is 800mA */
+#define MMC_CAP_CMD23 (1 << 30) /* CMD23 supported. */
mmc_pm_flag_t pm_caps; /* supported pm features */
@@ -366,5 +367,10 @@
{
return host->pm_flags & MMC_PM_WAKE_SDIO_IRQ;
}
+
+static inline int mmc_host_cmd23(struct mmc_host *host)
+{
+ return host->caps & MMC_CAP_CMD23;
+}
#endif