serial: Call set_custom_baudrate() thrice
Call the function before tcsetattr() settings are known, then again
with settings prepared but not yet applied and finally a third time
after tcsetattr().
Darwin support needs this change; there custom_baud code must be
called to modify the settings passed to tcsetattr() and then again
after tcsetattr() returns.
The change should be non-functional on all currently supported systems;
current code calls set_custom_baudrate() before any tcsetattr()
settings are prepared, so we have three stages in total.
This change originates from discussion of the macOS patch proposed by
Denis Ahrens in https://review.coreboot.org/c/flashrom/+/67822
Change-Id: I40cc443cfb7bf6b212b31826d437b898cc13c427
Signed-off-by: Peter Stuge <peter@stuge.se>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/70569
Original-Reviewed-by: Thomas Heijligen <src@posteo.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73479
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/custom_baud.c b/custom_baud.c
index 28f182c..8bbe6cc 100644
--- a/custom_baud.c
+++ b/custom_baud.c
@@ -19,7 +19,7 @@
#include "custom_baud.h"
/* Stub, should not get called. */
-int set_custom_baudrate(int fd, unsigned int baud)
+int set_custom_baudrate(int fd, unsigned int baud, const enum custom_baud_stage stage, void *tio_wanted)
{
errno = ENOSYS; /* Hoping "Function not supported" will make you look here. */
return -1;
diff --git a/custom_baud_linux.c b/custom_baud_linux.c
index 2d5f261..761d496 100644
--- a/custom_baud_linux.c
+++ b/custom_baud_linux.c
@@ -29,9 +29,13 @@
* for more info.
*/
-int set_custom_baudrate(int fd, unsigned int baud)
+int set_custom_baudrate(int fd, unsigned int baud, const enum custom_baud_stage stage, void *tio_wanted)
{
struct termios2 tio;
+
+ if (stage != BEFORE_FLAGS)
+ return 0;
+
if (ioctl(fd, TCGETS2, &tio)) {
return -1;
}
diff --git a/include/custom_baud.h b/include/custom_baud.h
index c8b8fc2..38e6cfc 100644
--- a/include/custom_baud.h
+++ b/include/custom_baud.h
@@ -22,7 +22,13 @@
unsigned int baud;
};
-int set_custom_baudrate(int fd, unsigned int baud);
+enum custom_baud_stage {
+ BEFORE_FLAGS = 0,
+ WITH_FLAGS,
+ AFTER_FLAGS
+};
+
+int set_custom_baudrate(int fd, unsigned int baud, const enum custom_baud_stage stage, void *tio_wanted);
/* Returns 1 if non-exact rate would be used, and setting a custom rate is supported.
The baudtable must be in ascending order and terminated with a 0-baud entry. */
diff --git a/serial.c b/serial.c
index 72f9ef6..cfc9b1e 100644
--- a/serial.c
+++ b/serial.c
@@ -179,6 +179,7 @@
}
msg_pdbg("Baud rate is %ld.\n", dcb.BaudRate);
#else
+ int custom_baud = (baud >= 0 && use_custom_baud(baud, sp_baudtable));
struct termios wanted, observed;
if (tcgetattr(fd, &observed) != 0) {
msg_perr_strerror("Could not fetch original serial port configuration: ");
@@ -186,8 +187,8 @@
}
wanted = observed;
if (baud >= 0) {
- if (use_custom_baud(baud, sp_baudtable)) {
- if (set_custom_baudrate(fd, baud)) {
+ if (custom_baud) {
+ if (set_custom_baudrate(fd, baud, BEFORE_FLAGS, NULL)) {
msg_perr_strerror("Could not set custom baudrate: ");
return 1;
}
@@ -198,7 +199,6 @@
msg_perr_strerror("Could not fetch serial port configuration: ");
return 1;
}
- msg_pdbg("Using custom baud rate.\n");
} else {
const struct baudentry *entry = round_baud(baud);
if (cfsetispeed(&wanted, entry->flag) != 0 || cfsetospeed(&wanted, entry->flag) != 0) {
@@ -212,6 +212,10 @@
wanted.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG | IEXTEN);
wanted.c_iflag &= ~(IXON | IXOFF | IXANY | ICRNL | IGNCR | INLCR);
wanted.c_oflag &= ~OPOST;
+ if (custom_baud && set_custom_baudrate(fd, baud, WITH_FLAGS, &wanted)) {
+ msg_perr_strerror("Could not set custom baudrate: ");
+ return 1;
+ }
if (tcsetattr(fd, TCSANOW, &wanted) != 0) {
msg_perr_strerror("Could not change serial port configuration: ");
return 1;
@@ -236,6 +240,13 @@
(long)observed.c_oflag, (long)wanted.c_oflag
);
}
+ if (custom_baud) {
+ if (set_custom_baudrate(fd, baud, AFTER_FLAGS, &wanted)) {
+ msg_perr_strerror("Could not set custom baudrate: ");
+ return 1;
+ }
+ msg_pdbg("Using custom baud rate.\n");
+ }
if (cfgetispeed(&observed) != cfgetispeed(&wanted) ||
cfgetospeed(&observed) != cfgetospeed(&wanted)) {
msg_pwarn("Could not set baud rates exactly.\n");