# # MMC/SD card drivers # comment "MMC/SD/SDIO Card Drivers" config MMC_BLOCK tristate "MMC block device driver" depends on BLOCK default y help Say Y here to enable the MMC block device driver support. This provides a block device driver, which you can use to mount the filesystem. Almost everyone wishing MMC support should say Y or M here. config MMC_BLOCK_BOUNCE bool "Use bounce buffer for simple hosts" depends on MMC_BLOCK default y help SD/MMC is a high latency protocol where it is crucial to send large requests in order to get high performance. Many controllers, however, are restricted to continuous memory (i.e. they can't do scatter-gather), something the kernel rarely can provide. Say Y here to help these restricted hosts by bouncing requests back and forth from a large buffer. You will get a big performance gain at the cost of up to 64 KiB of physical memory. If unsure, say Y here. config SDIO_UART tristate "SDIO UART/GPS class support" help SDIO function driver for SDIO cards that implements the UART class, as well as the GPS class which appears like a UART. config MMC_TEST tristate "MMC host test driver" default n help Development driver that performs a series of reads and writes to a memory card in order to expose certain well known bugs in host controllers. The tests are executed by writing to the "test" file in sysfs under each card. Note that whatever is on your card will be overwritten by these tests. This driver is only of interest to those developing or testing a host driver. Most people should say N here.