# # 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_MINORS int "Number of minors per block device" depends on MMC_BLOCK range 4 256 default 8 help Number of minors per block device. One is needed for every partition on the disk (plus one for the whole disk). Number of total MMC minors available is 256, so your number of supported block devices will be limited to 256 divided by this number. Default is 8 to be backwards compatible with previous hardwired device numbering. If unsure, say 8 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" depends on TTY 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" 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 debugfs 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. config MMC_SIMULATE_MAX_SPEED bool "Turn on maximum speed control per block device" depends on MMC_BLOCK help Say Y here to enable MMC device speed limiting. Used to test and simulate the behavior of the system when confronted with a slow MMC. Enables max_read_speed, max_write_speed and cache_size attributes to control the write or read maximum KB/second speed behaviors. If unsure, say N here. config MMC_FFU bool "FFU SUPPORT" depends on MMC != n help This is an option to run firmware update on eMMC 5.0. Field firmware updates (FFU) enables features enhancment in the field. config MMCQD_CPU_AFFINITY bool "mmcqd cpu affinity" depends on SMP default n help Define the cpu affinity mask for the mmcqd thread. config MMCQD_CPU_AFFINITY_VALUE string "mmcqd cpu affinity value" depends on MMCQD_CPU_AFFINITY default "f" help When MMCQD_CPU_AFFINITY is defined, this config is used to set the value. On top of power benefits, limiting the mmcqd thread to certain cpu's can provide a perf benefit due to less disturbances to fg and other threads of importance by reducing potential migrations and also mmcqd itself getting preempted by other threads. The cpu affinity mask is basically a hex string which represents the bitmask of the affinity, each bit represents a cpu core. For e.g. to limit mmcqd to 0'th core, use the following: CONFIG_MMCQD_CPU_AFFINITY_VALUE='1'