Summary:
- I thought this cs is needed to avoid data corruption
- For example, while executing uart_xmitchar() in the interrupt
handler on CPU0, an application running on CPU1 can call
uart_putxmitchar() via write()->uart_write().
- In this case, taking xmit.sem in uart_write() will wait for CPU0
to finish uart_xmitchar() because CPU0 has already taken a cs
in uart_xmitchar() then nxsem_wait() on CPU0 takes a new cs
inside (and release the cs when returning but it's OK)
- Then uart_write() on CPU1 disables UART TX, so uart_xmitchar()
on CPU0 will not be called while executing uart_write() on CPU1.
- So this critical section in uart_putxmitchar() can be removed.
Impact:
- None
Testing:
- Tested with spresense:wifi_smp, esp32-devkitc:smp
Reported-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
This is addressing an issue where Rx interrupts were not restored for
cdcacm after the buffer had been filled (in a burst).
The Rx interrupts were only restored after the watchdog timeout of 200ms
fired.
This happened because CONFIG_SERIAL_RXDMA was set, however, for the
cdcacm driver this does not actually matter as it is relying on
uart_enablerxint to be called via the ops table.
This patch makes sure that uart_enablerxint and uart_disablerxint are
always called, independent of CONFIG_SERIAL_RXDMA, relying on the ops
table to be correct for the case where it should be only a no-op.
Re-check RX queue status after uart_enablerxint() and before blocking
the reading task on the receive semaphore. cdcacm (and maybe other UART
drivers) can push buffered data into the receive queue during
uart_enablerxint(), leading to a blocked task while data is already
available.
Signed-off-by: Tido Klaassen <tido@4gh.eu>
Follow the POSIX description.
SIGTSTP should be sent when the Ctrl-Z characters is encountered, not SIGSTP.
Testing:
Built with hifive1-revb:nsh (CONFIG_SERIAL_TERMIOS=y, CONFIG_SIG_DEFAULT=y and CONFIG_TTY_SIGTSTP=y)
There is a good case on sim platform:
When we input some cmd and click enter key to start application in terminal,
this context will change to application from IDLE loop. Althrough entey key '\r'
has been received to recv buffer and complete post semaphore of reader, but
pollnotify may not be called because context change. So when application run
poll function, because no events happend and poll enter wait, context will
again change to IDLE loop, this pollnotify of IDLE loop will run to send poll
events, poll function of applicaton will wake up. It's wrong!
Change-Id: I812a889f2e90781a9c3cb4b0251cccc4d32bebd1
Signed-off-by: dongjiuzhu <dongjiuzhu1@xiaomi.com>
boards/z80/ez80/z20x/configs/w25boot/defconfig: Increase size of serial Tx buffer.
boards/z80/ez80/z20x/src/w25_main.c: Add some fflush() in necessary places. Greatly improves the usability of the UI.
boards/z80/ez80/z20x/README.txt: Trival update to README
drivers/serial/serial.c and tcdrain.c: Correct some typos.
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
drivers: serial: Fix data corruption when outputting data in SMP mode
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
arch/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
sched/ audio/ crypto/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
Documentation/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
fs/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
graphics/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
net/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
drivers/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
include/, syscall/, wireless/: Removed all references to CONFIG_DISABLE_POLL. The standard POSIX poll() can not longer be disabled.
configs/: Remove all references to CONFIG_DISABLE_POLL. Standard POSIX poll can no longer be disabled.
libs/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
syscall/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
wireless/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
Documentation/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
include/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
drivers/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
sched/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
configs: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/xtensa: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/z80: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/x86: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/renesas and arch/risc-v: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/or1k: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/misoc: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/mips: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/avr: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/arm: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
drivers/serial/Kconfig: It is no longer necessary to restrict Ctrl-C handling to the FLAT build
sched/signal: Add a new configuration option to select signal default actions, separate handling of signal default actions from both task startup logic and from the serial TTY Ctrl-C logic. Add a signal set in the group structure to keep track of what signals have been set to the default action. In dispatching signals in PROTECTED or KERNEL mode, use this signal set to determine if the default signal handler is attached and dispatch the signal in kernel mode for the default actions.
drivers/serial: Add Ctrl-C/Ctrl-X support. This is an initial working implementation that still requires that several details be resolved.
sched/task/task_start.c: Add default signal action to SIGKILL.
Squashed commit of the following:
sched: Rename all use of system_t to clock_t.
syscall: Rename all use of system_t to clock_t.
net: Rename all use of system_t to clock_t.
libs: Rename all use of system_t to clock_t.
fs: Rename all use of system_t to clock_t.
drivers: Rename all use of system_t to clock_t.
arch: Rename all use of system_t to clock_t.
include: Remove definition of systime_t; rename all use of system_t to clock_t.
According to the specification, the close function must wait until all data
has been written before it closes the file (except O_NONBLOCK is set). The
maximum waiting time for this is not specified.
To be able to edit the file list of the process, the close function has to lock
the file list semaphore. After that the close function of the serial driver is
called.
Waiting for the complete transmission of all data is done in the serial driver.
This causes the semaphore to remain locked until all data has been sent.
However, no other thread of the process can edit the file list for that time
(open, close, dup2, etc.). This is not optimal in a multithreaded environment.
Therefore, we have to keep the waiting time within the driver as short as possible.
Squashed commit of the following:
Change all calls to usleep() in the OS proper to calls to nxsig_usleep()
sched/signal: Add a new OS internal function nxsig_usleep() that is functionally equivalent to usleep() but does not cause a cancellaption point and does not modify the errno variable.
sched/signal: Add a new OS internal function nxsig_sleep() that is functionally equivalent to sleep() but does not cause a cancellaption point.
This commit backs out most of commit b4747286b1. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point.
In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable.
In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable.
sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post().
sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy().
libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
device, while it is being terminated by pthread_cancel(), then
uart_close() gets called, but the semaphore (dev->recv.sem in the above
example) is still blocked.
This means that once the serial device is opened next time, data will
arrive on the serial port (and driver interrupts handled as normal), but
the received characters never arrive in the reader thread.
This patch addresses the problem by re-initializing the semaphores on the
last uart_close() on the device.
