tegrakernel/kernel/kernel-4.9/drivers/mmc/card/Kconfig

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2022-02-16 09:13:02 -06:00
#
# 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'