Yoshihiro YUNOMAE
aef9a7bd9b
serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers ...
Add tunable RX interrupt trigger I/F of FIFO buffers.
Serial devices are used as not only message communication devices but control
or sending communication devices. For the latter uses, normally small data
will be exchanged, so user applications want to receive data unit as soon as
possible for real-time tendency. If we have a sensor which sends a 1 byte data
each time and must control a device based on the sensor feedback, the RX
interrupt should be triggered for each data.
According to HW specification of serial UART devices, RX interrupt trigger
can be changed, but the trigger is hard-coded. For example, RX interrupt trigger
in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets
the trigger to only 8bytes.
This patch makes some devices change RX interrupt trigger from userland.
<How to use>
- Read current setting
# cat /sys/class/tty/ttyS0/rx_trig_bytes
8
- Write user setting
# echo 1 > /sys/class/tty/ttyS0/rx_trig_bytes
# cat /sys/class/tty/ttyS0/rx_trig_bytes
1
<Support uart devices>
- 16550A and Tegra (1, 4, 8, or 14 bytes)
- 16650V2 (8, 16, 24, or 28 bytes)
- 16654 (8, 16, 56, or 60 bytes)
- 16750 (1, 16, 32, or 56 bytes)
<Change log>
Changes in V9:
- Use attr_group instead of dev_spec_attr_group of uart_port structure
Changes in V8:
- Divide this patch from V7's patch based on Greg's comment
Changes in V7:
- Add Documentation
- Change I/F name from rx_int_trig to rx_trig_bytes because the name
rx_int_trig is hard to understand how users specify the value
Changes in V6:
- Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h,
rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to
UART_FCR_R_TRIG_BITS()
- Change following function names:
convert_fcr2val() => fcr_get_rxtrig_bytes()
convert_val2rxtrig() => bytes_to_fcr_rxtrig()
- Fix typo in serial8250_do_set_termios()
- Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig()
- Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables
(but UI remains rx_int_trig)
- Change the meaningless variable name 'val' to 'bytes' following functions:
fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(),
do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig()
- Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in
fcr_get_rxtrig_bytes()
- Use conf_type->rxtrig_bytes[0] instead of switch statement for support check
in register_dev_spec_attr_grp()
- Delete the checking whether a user changed FCR or not when minimum buffer
is needed in serial8250_do_set_termios()
Changes in V5.1:
- Fix FCR_RX_TRIG_MAX_STATE definition
Changes in V5:
- Support Tegra, 16650V2, 16654, and 16750
- Store default FCR value to up->fcr when the port is first created
- Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[]
in convert_fcr2val() and convert_val2rxtrig()
Changes in V4:
- Introduce fifo_bug flag in uart_8250_port structure
This is enabled only when parity is enabled and UART_BUG_PARITY is enabled
for up->bugs. If this flag is enabled, user cannot set RX trigger.
- Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and
at convert_val2rxtrig()
- Set the nearest lower RX trigger when users input a meaningless value at
convert_val2rxtrig()
- Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos()
- Set fcr = up->fcr in the begging of serial8250_do_set_termios()
Changes in V3:
- Change I/F from ioctl(2) to sysfs(rx_int_trig)
Changed in V2:
- Use _IOW for TIOCSFIFORTRIG definition
- Pass the interrupt trigger value itself
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:23:35 -07:00
Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
2014-06-10 10:28:45 -07:00
can: unify identifiers to ensure unique include processing
2014-05-19 09:38:24 +02:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
2014-06-12 23:06:23 -07:00
Merge branch 'for-v3.16/ti-clk-drv' of github.com:t-kristo/linux-pm into clk-next
2014-06-10 16:53:25 -07:00
fsl /bestcomm
This pull-request contains some misplaced patches from Tony
2014-06-12 12:42:32 -07:00
Input: add common DT binding for touchscreens
2014-05-29 00:05:59 -07:00
irqchip: gic: Use mask field in GICC_IAR
2014-05-19 00:35:23 +00:00
isdn/capi: move capi_info2str to capidrv.c
2014-06-04 23:13:41 -07:00
rtc: s5m: use shorter time of register update
2014-06-10 15:34:47 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2014-06-12 14:27:40 -07:00
mlx5_core: Store MR attributes in mlx5_mr_core during creation and after UMR
2014-05-27 11:53:06 -07:00
mmc: sdhci: track whether preset mode is currently enabled in hardware
2014-05-22 08:33:30 -04:00
MTD updates for 3.16:
2014-06-11 08:35:34 -07:00
New driver for Sensirion SHTC1 humidity / temperature sensor
2014-06-14 14:43:23 -07:00
Merge remote-tracking branch 'regulator/fix/core' into regulator-linus
2014-06-16 16:05:56 +01:00
mm: update comment for DEFAULT_MAX_MAP_COUNT
2014-06-04 16:54:05 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2014-06-12 14:27:40 -07:00
ssb: sprom: add dev_id field for value overriding standard ID
2014-05-19 16:42:15 -04:00
NFS client updates for Linux 3.16
2014-06-10 15:02:42 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2014-06-12 14:27:40 -07:00
Merge branch 'acpi-enumeration'
2014-06-03 23:12:20 +02:00
backlight: Add backlight device (un)registration notification
2014-05-27 01:29:01 +02:00
block: add support for limiting gaps in SG lists
2014-06-24 16:22:24 -06:00
blk-mq: bitmap tag: fix races on shared ::wake_index fields
2014-06-17 22:12:35 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2014-06-12 10:30:18 -07:00
block: add support for limiting gaps in SG lists
2014-06-24 16:22:24 -06:00
include/linux/bootmem.h: cleanup the comment for BOOTMEM_ flags
2014-06-04 16:54:04 -07:00
fs/buffer.c: remove block_write_full_page_endio()
2014-06-04 16:54:02 -07:00
fs,userns: Change inode_capable to capable_wrt_inode_uidgid
2014-06-10 13:57:22 -07:00
Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
2014-06-09 14:56:07 -07:00
cgroup: disallow debug controller on the default hierarchy
2014-05-19 16:37:06 -04:00
The clock framework changes for 3.16 are pretty typical: mostly clock
2014-06-07 20:27:30 -07:00
of: consolidate linker section OF match table declarations
2014-05-20 14:25:24 -05:00
mm, compaction: embed migration mode in compact_control
2014-06-04 16:54:06 -07:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-06-12 19:18:49 -07:00
connector: allow multiple messages to be sent in one packet
2014-05-27 13:56:21 -07:00
console: Use explicit pointer type for vc_uni_pagedir* fields
2014-05-28 13:37:21 -07:00
idle: remove cpu_idle() forward declarations
2014-06-06 16:08:18 -07:00
cpufreq: add support for intermediate (stable) frequencies
2014-06-05 23:32:29 +02:00
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
2014-06-09 18:10:34 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2014-06-12 14:27:40 -07:00
mm: page_alloc: use jump labels to avoid checking number_of_cpusets
2014-06-04 16:54:08 -07:00
PM / devfreq: Add devm_devfreq_{register,unregister}_opp_notfier function
2014-05-24 22:33:41 +09:00
dm: remove symbol export for dm_set_device_limits
2014-06-04 09:46:34 -04:00
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into next
2014-06-05 15:57:04 -07:00
cma: add placement specifier for "cma=" kernel parameter
2014-06-04 16:53:57 -07:00
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into next
2014-06-05 15:57:04 -07:00
Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
2014-06-10 10:28:45 -07:00
Revert "block: add __init to elv_register"
2014-06-22 16:34:11 -06:00
ethtool: Replace ethtool_ops::{get,set}_rxfh_indir() with {get,set}_rxfh()
2014-06-03 02:42:44 +01:00
f2fs: large volume support
2014-06-04 13:34:30 +09:00
net: filter: cleanup A/X name usage
2014-06-11 00:13:16 -07:00
ALSA: firewire/bebob: Add a workaround for M-Audio special Firewire series
2014-05-26 14:33:10 +02:00
File locking related bugfixes for v3.16 (pile #2 )
2014-06-21 16:40:30 -10:00
Lots of tweaks, small fixes, optimizations, and some helper functions
2014-06-09 16:39:15 -07:00
include/linux/gfp.h: exclude duplicate header
2014-06-04 16:54:10 -07:00
goldfish: fix >> 32 warning
2014-05-20 10:30:40 +09:00
Merge branches 'for-3.16/i2c-hid', 'for-3.16/rmi4', 'for-3.16/sony' and 'for-3.16/thingm' into for-linus
2014-06-04 13:09:43 +02:00
hugetlb: rename hugepage_migration_support() to ..._supported()
2014-06-04 16:54:12 -07:00
virtio-rng: fixes for device registration/unregistration
2014-05-19 09:26:40 +09:30
idr: reorder the fields
2014-06-06 16:08:13 -07:00
wireless: add missing WLAN_EID_BSS_INTOLERANT_CHL_REPORT
2014-05-28 16:22:47 +02:00
bridge: memorize and export selected IGMP/MLD querier port
2014-06-10 23:50:47 -07:00
net-next:v4: Add support to configure SR-IOV VF minimum and maximum Tx rate through ip tool.
2014-05-23 15:04:02 -04:00
macvlan: add netpoll support
2014-06-02 16:05:24 -07:00
team: fix mtu setting
2014-06-02 14:56:01 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2014-05-24 00:32:30 -04:00
init.h: Update initcall_sync variants to fix build errors
2014-05-27 14:26:31 -07:00
Merge commit ' 3cf2f34' into sched/core, to fix build error
2014-06-12 13:46:37 +02:00
include/linux/jump_label.h: expose the reference count
2014-06-04 16:54:08 -07:00
Merge branch 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2014-07-10 11:38:23 -07:00
Merge branch 'serge-next-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security
2014-06-10 10:05:36 -07:00
mm: introduce kmemleak_update_trace()
2014-06-06 16:08:17 -07:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-06-12 19:18:49 -07:00
ktime: add ktime_after and ktime_before helper
2014-06-11 12:23:17 -07:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-06-12 19:42:15 -07:00
drivers/rtc/rtc-cmos.c: drivers/char/rtc.c features for DECstation support
2014-06-06 16:08:07 -07:00
mcb: Add support for shared PCI IRQs
2014-05-27 17:38:11 -07:00
memblock: introduce memblock_alloc_range()
2014-06-04 16:53:57 -07:00
memcg: cleanup kmem cache creation/destruction functions naming
2014-06-04 16:54:08 -07:00
mem-hotplug: implement get/put_online_mems
2014-06-04 16:53:59 -07:00
hugetlb: restrict hugepage_migration_support() to x86_64
2014-06-04 16:53:51 -07:00
mm, migration: add destination page freeing callback
2014-06-04 16:54:06 -07:00
miscdevice.h: Simple syntax fix to make pointers consistent.
2014-05-27 17:43:11 -07:00
Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
2014-06-05 08:05:29 -07:00
Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
2014-06-05 08:05:29 -07:00
mm: pass VM_BUG_ON() reason to dump_page()
2014-06-04 16:53:58 -07:00
mm: page_alloc: use unsigned int for order in more places
2014-06-04 16:54:09 -07:00
net: Fix GSO constants to match NETIF flags
2014-06-15 01:00:49 -07:00
net: Fix GSO constants to match NETIF flags
2014-06-15 01:00:49 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2014-06-03 23:32:12 -07:00
pnfs: support multiple verfs per direct req
2014-05-29 11:11:48 -04:00
nfs4: remove unused CHANGE_SECURITY_LABEL
2014-06-06 19:22:49 -04:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2014-06-12 10:30:18 -07:00
nfs: page group syncing in write path
2014-05-29 11:11:45 -04:00
pnfs: support multiple verfs per direct req
2014-05-29 11:11:48 -04:00
ieee802154: add netlink interfaces for llsec
2014-05-16 17:23:41 -04:00
kernel/watchdog.c: print traces for all cpus on lockup detection
2014-06-23 16:47:44 -07:00
NVMe: Fix hot cpu notification dead lock
2014-06-13 10:43:34 -04:00
DeviceTree for 3.16:
2014-06-04 10:02:38 -07:00
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into next
2014-06-05 15:57:04 -07:00
of/fdt: add FDT address translation support
2014-05-20 15:19:25 -05:00
gpio: make of_get_named_gpiod_flags() private
2014-05-21 11:14:46 +02:00
of/irq: do irq resolution in platform_get_irq_byname()
2014-05-23 11:40:25 +09:00
net: of_mdio: add of_mdiobus_link_phydev()
2014-05-29 15:23:29 -07:00
of/irq: provide more wrappers for !CONFIG_OF
2014-06-04 04:45:46 -05:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next
2014-06-04 08:50:34 -07:00
of: consolidate linker section OF match table declarations
2014-05-20 14:25:24 -05:00
MMC highlights for 3.16:
2014-06-10 14:35:22 -07:00
MMC highlights for 3.16:
2014-06-10 14:35:22 -07:00
kexec: save PG_head_mask in VMCOREINFO
2014-06-23 16:47:43 -07:00
mm: page_alloc: reduce number of times page_to_pfn is called
2014-06-04 16:54:09 -07:00
mm: non-atomically mark page accessed during page cache allocation where possible
2014-06-04 16:54:10 -07:00
Merge branch 'pci/iommu' into next
2014-06-02 16:18:48 -06:00
core: fix typo in percpu read_mostly section
2014-07-01 16:45:22 -04:00
Merge branch 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu.git into for-3.16
2014-06-04 12:50:47 -04:00
Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
2014-06-09 14:56:07 -07:00
perf: Differentiate exec() and non-exec() comm events
2014-06-06 07:56:22 +02:00
net: phylib: add link_change_notify callback to phy device
2014-06-21 15:50:00 -07:00
net: phy: fix sparse warning in fixed.c
2014-06-05 15:38:57 -07:00
lib/plist: add plist_requeue
2014-06-04 16:54:07 -07:00
PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily
2014-05-16 23:15:44 +02:00
PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily
2014-05-16 23:15:44 +02:00
power_supply: allow power supply devices registered w/o wakeup source
2014-05-30 13:45:25 +02:00
kernel/printk: use symbolic defines for console loglevels
2014-06-04 16:54:17 -07:00
init/main.c: remove an ifdef
2014-06-04 16:54:21 -07:00
sparc: fix sparse warnings in smp_32.c + smp_64.c
2014-05-18 19:01:33 -07:00
ptrace,x86: force IRET path after a ptrace_stop()
2014-07-03 17:27:23 -07:00
pwm: modify PWM_LOOKUP to initialize all struct pwm_lookup members
2014-05-21 11:19:36 +02:00
rcu: Provide API to suppress stall warnings while sysrc runs
2014-05-19 10:52:04 -07:00
ring-buffer: Check if buffer exists before polling
2014-06-10 09:46:00 -04:00
mm/rmap.c: cleanup ttu_flags
2014-06-04 16:54:12 -07:00
locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK
2014-06-05 10:38:45 +02:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-06-12 19:42:15 -07:00
Merge branch 'serge-next-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sergeh/linux-security
2014-06-10 10:05:36 -07:00
serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers
2014-07-17 18:23:35 -07:00
Serial: allow port drivers to have a default attribute group
2014-07-17 18:21:21 -07:00
ipc/shm.c: increase the defaults for SHMALL, SHMMAX
2014-06-06 16:08:14 -07:00
signals: introduce kernel_sigaction()
2014-06-06 16:08:12 -07:00
net: add skb_pop_rcv_encapsulation
2014-06-15 01:00:50 -07:00
memcg: cleanup kmem cache creation/destruction functions naming
2014-06-04 16:54:08 -07:00
idle: remove cpu_idle() forward declarations
2014-06-06 16:08:18 -07:00
iovec: move memcpy_from/toiovecend to lib/iovec.c
2014-06-27 11:47:58 -07:00
fs/splice.c: remove unneeded exports
2014-06-12 00:21:11 -04:00
lib: add glibc style strchrnul() variant
2014-05-23 11:23:27 +09:00
PM / hibernate: introduce "nohibernate" boot parameter
2014-06-16 23:29:39 +02:00
mm/vmscan.c: use DIV_ROUND_UP for calculation of zone's balance_gap and correct comments.
2014-06-04 16:54:11 -07:00
swap: change swap_list_head to plist, add swap_avail_head
2014-06-04 16:54:07 -07:00
x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels
2014-06-04 16:53:55 -07:00
x86: enable DMA CMA with swiotlb
2014-06-04 16:53:57 -07:00
mm: constify nmask argument to set_mempolicy()
2014-06-04 16:54:03 -07:00
sysfs.h: don't return a void-valued expression in sysfs_remove_file
2014-05-27 14:29:56 -07:00
tcp: make cwnd-limited checks measurement-based, and gentler
2014-05-22 12:04:49 -04:00
mm: get rid of __GFP_KMEMCG
2014-06-04 16:53:56 -07:00
mm: disable zone_reclaim_mode by default
2014-06-04 16:53:59 -07:00
drivers: tty: Merge alloc_tty_struct and initialize_tty_struct
2014-07-11 17:54:28 -07:00
tty: Document locking for tty driver methods
2014-07-10 16:05:19 -07:00
DMA-API: Clarify physical/bus address distinction
2014-05-20 16:54:21 -06:00
net: Make enabling of zero UDP6 csums more restrictive
2014-05-23 16:28:53 -04:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
2014-06-28 09:43:58 -07:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-06-12 19:18:49 -07:00
USB: separate usb_address0 mutexes for each bus
2014-05-27 16:11:49 -07:00
usb-storage/SCSI: Add broken_fua blacklist flag
2014-06-30 22:47:18 -07:00
drivers/vfio: Rework offsetofend()
2014-05-30 11:35:54 -06:00
virtio-scsi.h: Add virtio_scsi_cmd_req_pi + VIRTIO_SCSI_F_T10_PI bits
2014-06-02 12:41:33 -07:00
mm,vmacache: add debug data
2014-06-04 16:53:57 -07:00
mm,vmacache: add debug data
2014-06-04 16:53:57 -07:00
workqueue: remove unused work_clear_pending()
2014-05-22 11:35:51 -04:00
mm/zbud.c: make size unsigned like unique callsite
2014-06-04 16:54:13 -07:00
