Make write to UDR and clearing of TXC bit in flush() atomic
to avoid race condition.
Fixes#3745 (second different issue introduced later but discussed
in the same issue)
Moving the head buffer pointer and setting interrupt flag is now
atomic in write(). Previously an intervening ISR could empty the
buffer before the second ISR is triggered causing retransmission.
Fixes: #3745 (original issue only)
New macro TX_BUFFER_ATOMIC makes the following code block atomic
only if the transmit buffer is larger than 256 bytes. SREG is restored
on completion.
The macro is then used to simplify code for availableForWrite()
Instead of checking for the NEW_LUFA_SIGNATURE once in program memory and then
setting a flag which is used for further checks, a function is used that always
checks program memory directly.
If a flag is used, there's a slight chance that its location in RAM could fall
on MAGIC_KEY_POS. In this case, an aborted USB auto-reset sequence may fail.
An auto-reset invoked using USB CDC is triggered by the port closing
(when set to 1200 baud). Closing of the port is indicated by DTR going inactive.
There is no need to have auto-reset invoked by a CDC_SET_LINE_CODING command.
Only the CDC_SET_CONTROL_LINE_STATE command, which indicates a change in the
state of DTR, should be used.
In the USB CDC code to invoke an auto-reset, the magic key location could be
restored before it had actually been saved. The sketch would then have a
corrupted value at this location. This fix prevents the value from being
restored if it hasn't previously been saved.
These functions were changed from private to protected in 99f2a27553 but the comments were not updated at that time.
In conjunction with equivalent pull requests to Arduino SAM Boards and Arduino SAMD Boards, solves https://github.com/arduino/Arduino/issues/6146.
This method originally flushed pending input bytes, which makes sense in
Stream. At some point it was changed to flush output bytes instead, but
it was never moved to Print to reflect this.
Since Stream inherits from Print, this should not really affect any
users of the Stream or Print classes. However to prevent problems with
existing implementations of the Print class that do not provide a
flush() implementation, a default implementation is provided. We should
probably remove this at some point in the future, though.
- "." is a string literal, and so is treated as the char '.' plus the null char '\0'.
- Single quotes reduces the necessary memory for this literal to only one char instead.
A string literal as the one actually present may require the use of the
method "write(const char *str)", so there could be also a performance overhead.
- Another reason to change quotes style is for consistency with line 235.
Signed-off-by: Patrick Roncagliolo <ronca.pat@gmail.com>
On Linux, setting autosuspend_delay_ms to N and control to auto allows the host pc to suspend the peripheral. Some Linux distro (Ubuntu, Mint) apply this behaviour by default.
If the sketch's prints where less frequent than N milliseconds the sketch prints would never arrive.
This patch allows sending a remote wakeup event to unsuspend the peripheral and allow the serial prints to be received.
to allow WebUSB development, provide a way to change the USB_VERSION reported
using an additional core.
The additional (webUSB) core will survive IDE and AVR core updates
In an excess of confidence, these defines were added to Leonardo's variant.h
3rd party boards sometimes avoid inheriting this variant but they still define USBCON, thus breaking the build
As I was not able to base the return types of `begin()` & `end()` off the c_str() function, I have changed the source so the features can be used by C++98 code, while still allowing ranged loops in C++11.
Replaces #4280, only checks for the bootloader once
Tested with Hoodloader2, should work with every LUFA-derived bootloader released after 2014 (.apitable_signatures section must be placed at end of the flash)
BootloaderAPITable.S :
.global BootloaderAPI_Signatures
BootloaderAPI_Signatures:
.long BOOT_START_ADDR ; Start address of the bootloader
.word 0xDF00 ; Signature for the CDC class bootloader
.word 0xDCFB ; Signature for a LUFA class bootloader
makefile:
BOOT_API_LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, .apitable_signatures, BootloaderAPI_Signatures, 8)
Avoid using the overload of print() for signed integer since a negative value is not allowed here.
This results in a smaller (unless print(int) is used somewhere else in the program) and faster code because the overload for unsigned integer is simpler.
Martino Facchin
John Holman
Scott Allen
Torben Nielsen
per1234
Cristian Maglie
Matthijs Kooijman
Eric Wieser
Cristian Maglie
liu nick
Sandeep Mistry
Patrick Roncagliolo
Iván Pérez
Niklas Mischkulnig
Kyle Chisholm
Arturo Guadalupi
Christopher Andrews
mattb5906
Benoît Blanchon