From f514bc1e89bc977f94457d9d279494a066827280 Mon Sep 17 00:00:00 2001 From: Vitor Soares Date: Fri, 31 Oct 2025 15:56:13 +0000 Subject: [PATCH] linux-serial-test: add patch to fix serial setup handling Add patch that restores user intent in serial setup handling. Upstream commit 77320571e63c ignores user input when RS485 was pre-configured, breaking loopback and flow-control tests. This patch ensures RS485 can be explicitly controlled while still respecting pre-existing configurations when appropriate. Signed-off-by: Vitor Soares Signed-off-by: Khem Raj --- ...etup-handling-to-respect-user-intent.patch | 133 ++++++++++++++++++ .../linux-serial-test_git.bb | 1 + 2 files changed, 134 insertions(+) create mode 100644 meta-oe/recipes-test/linux-serial-test/files/0001-Fix-serial-setup-handling-to-respect-user-intent.patch diff --git a/meta-oe/recipes-test/linux-serial-test/files/0001-Fix-serial-setup-handling-to-respect-user-intent.patch b/meta-oe/recipes-test/linux-serial-test/files/0001-Fix-serial-setup-handling-to-respect-user-intent.patch new file mode 100644 index 0000000000..2360d1ee0c --- /dev/null +++ b/meta-oe/recipes-test/linux-serial-test/files/0001-Fix-serial-setup-handling-to-respect-user-intent.patch @@ -0,0 +1,133 @@ +From 8d4f9a1a77f59eb3ed79267f58fac949835aebfc Mon Sep 17 00:00:00 2001 +From: Vitor Soares +Date: Thu, 30 Oct 2025 14:52:57 +0000 +Subject: [PATCH] Fix serial setup handling to respect user intent + +Commit 77320571e63c ("Check if rs485 is already configured on the port") +attempted to respect RS485 settings already configured on the port (e.g. +via Device Tree). However, it unintentionally ignored user input, +causing issues such as: +- Inability to change delay settings +- Failure to explicitly disable RS485 +- Broken UART loopback and RTS/CTS flow-control tests when RS485 was +pre-enabled + +The original intent was valid for existing configurations (bare -q), but +the tool should prioritize user intent, especially in testing scenarios. + +This update restores predictable, user-driven behavior: +- RS485 can be explicitly enabled, disabled, or reconfigured +- Current configurations are respected when appropriate + +Upstream-Status: Submitted [https://github.com/cbrake/linux-serial-test/pull/68] +Fixes: 77320571e63c ("Check if rs485 is already configured on the port") +Signed-off-by: Vitor Soares +--- + linux-serial-test.c | 48 ++++++++++++++++++++++++++++----------------- + 1 file changed, 30 insertions(+), 18 deletions(-) + +diff --git a/linux-serial-test.c b/linux-serial-test.c +index 294f53882570..119bf58e663d 100644 +--- a/linux-serial-test.c ++++ b/linux-serial-test.c +@@ -60,6 +60,7 @@ int _cl_no_tx_param = 0; + int _cl_rx_delay = 0; + int _cl_tx_delay = 0; + int _cl_tx_bytes = 0; ++int _cl_rs485 = 0; + int _cl_rs485_after_delay = -1; + int _cl_rs485_before_delay = 0; + int _cl_rs485_rts_after_send = 0; +@@ -315,7 +316,9 @@ static void display_help(void) + " -q, --rs485 Enable RS485 direction control on port, and set delay from when TX is\n" + " finished and RS485 driver enable is de-asserted. Delay is specified in\n" + " bit times. To optionally specify a delay from when the driver is enabled\n" +- " to start of TX use 'after_delay.before_delay' (-q 1.1)\n" ++ " to start of TX use 'after_delay.before_delay' (-q 1.1). If no value is\n" ++ " given, delay defaults to 0. Existing RS485 configuration is respected if\n" ++ " already enabled.\n" + " -Q, --rs485_rts Deassert RTS on send, assert after send. Omitting -Q inverts this logic.\n" + " -m, --no-modem Do not clobber against any modem lines.\n" + " -o, --tx-time Number of seconds to transmit for (defaults to 0, meaning no limit)\n" +@@ -335,7 +338,7 @@ static void process_options(int argc, char * argv[]) + { + for (;;) { + int option_index = 0; +- static const char *short_options = "hb:p:d:D:TRsSy:z:cBertq:Qml:a:w:o:i:P:kKAI:O:W:Znf"; ++ static const char *short_options = "hb:p:d:D:TRsSy:z:cBertq::Qml:a:w:o:i:P:kKAI:O:W:Znf"; + static const struct option long_options[] = { + {"help", no_argument, 0, 0}, + {"baud", required_argument, 0, 'b'}, +@@ -359,7 +362,7 @@ static void process_options(int argc, char * argv[]) + {"rx-delay", required_argument, 0, 'l'}, + {"tx-delay", required_argument, 0, 'a'}, + {"tx-bytes", required_argument, 0, 'w'}, +- {"rs485", required_argument, 0, 'q'}, ++ {"rs485", optional_argument, 0, 'q'}, + {"rs485_rts", no_argument, 0, 'Q'}, + {"no-modem", no_argument, 0, 'm'}, + {"tx-time", required_argument, 0, 'o'}, +@@ -467,8 +470,12 @@ static void process_options(int argc, char * argv[]) + } + case 'q': { + char *endptr; +- _cl_rs485_after_delay = strtol(optarg, &endptr, 0); +- _cl_rs485_before_delay = strtol(endptr+1, &endptr, 0); ++ _cl_rs485 = 1; ++ ++ if (optarg) { ++ _cl_rs485_after_delay = strtol(optarg, &endptr, 0); ++ _cl_rs485_before_delay = strtol(endptr+1, &endptr, 0); ++ } + break; + } + case 'Q': +@@ -707,15 +714,20 @@ static void setup_serial_port(int baud) + + /* enable/disable rs485 direction control, first check if RS485 is supported */ + if(ioctl(_fd, TIOCGRS485, &rs485) < 0) { +- if (_cl_rs485_after_delay >= 0) { ++ if (_cl_rs485) { + /* error could be because hardware is missing rs485 support so only print when actually trying to activate it */ + perror("Error getting RS-485 mode"); + } + } else { +- if (rs485.flags & SER_RS485_ENABLED) { +- printf("RS485 already enabled on port, ignoring delays if set\n"); +- } else { +- if (_cl_rs485_after_delay >= 0) { ++ if (_cl_rs485) { ++ /* Skip reconfiguration if already enabled with default delays */ ++ if ((_cl_rs485_after_delay < 0) && (rs485.flags & SER_RS485_ENABLED)) { ++ printf("RS485 already enabled on port with default settings\n"); ++ } else { ++ /* Default to 0 if not specified */ ++ if (_cl_rs485_after_delay < 0) { ++ _cl_rs485_after_delay = 0; ++ } + /* enable RS485 */ + rs485.flags |= SER_RS485_ENABLED | SER_RS485_RX_DURING_TX | + (_cl_rs485_rts_after_send ? SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND); +@@ -725,14 +737,14 @@ static void setup_serial_port(int baud) + if(ioctl(_fd, TIOCSRS485, &rs485) < 0) { + perror("Error setting RS-485 mode"); + } +- } else { +- /* disable RS485 */ +- rs485.flags &= ~(SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND); +- rs485.delay_rts_after_send = 0; +- rs485.delay_rts_before_send = 0; +- if(ioctl(_fd, TIOCSRS485, &rs485) < 0) { +- perror("Error setting RS-232 mode"); +- } ++ } ++ } else { ++ /* disable RS485 */ ++ rs485.flags &= ~(SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND); ++ rs485.delay_rts_after_send = 0; ++ rs485.delay_rts_before_send = 0; ++ if(ioctl(_fd, TIOCSRS485, &rs485) < 0) { ++ perror("Error setting RS-232 mode"); + } + } + } diff --git a/meta-oe/recipes-test/linux-serial-test/linux-serial-test_git.bb b/meta-oe/recipes-test/linux-serial-test/linux-serial-test_git.bb index 7a206319e7..78fd9d3b1c 100644 --- a/meta-oe/recipes-test/linux-serial-test/linux-serial-test_git.bb +++ b/meta-oe/recipes-test/linux-serial-test/linux-serial-test_git.bb @@ -6,6 +6,7 @@ LIC_FILES_CHKSUM = "file://LICENSES/MIT;md5=544799d0b492f119fa04641d1b8868ed" SRC_URI = "git://github.com/cbrake/linux-serial-test.git;protocol=https;branch=master \ file://0001-linux-serial-test.c-fix-returned-error-code.patch \ file://0002-linux-serial-test.c-fix-potential-hang-in-while-loop.patch \ + file://0001-Fix-serial-setup-handling-to-respect-user-intent.patch \ " PV = "0+git" SRCREV = "1a81f3c7be086ee01a9be8589a606426276c86d5"