Cannot open an usb serial port

Question

Created Oct ’19

Replies 4

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Views 4.6k

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With the 10.15.1 Beta (19B68f) when I try to open an USB serial port, I get a port already in use. But the lsof doesn't show this port.

I tried to reboot my computer, but I have always the same error.

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Answer 1

jbdamiano OP

Oct ’19

The problem is still present on Beta 3

The system call open on the /dev return -1 and errno 16

The device is a FT232R USB UART (Vendor FTDI)

The source code to reproduce my issue on my usb serial

 #include 
#include 
#include 
#include 
#include 
#include 
 
int main(int argc, char **argv) {
 
 
    char file[] = "/dev/tty.usbserial-A600QJHB";
 
 
    int fd = open(file, 0x20006, 0x0);
 
 
    if (fd == -1) {
        printf("Cannot open device %s errno %d\n", file, errno);
        return -1;
    }
    printf("success\n");
 
    clode(fd);
    return 0;
}

On Catalina 10.15 I have the display of

Success

on 10.15.1 Beta

Cannot open device /dev/tty.usbserial-A600QJHB errno 16 (Device in use)

The device is not in use.

The console log:

On 10.15

par défaut 09:30:00.056107+0200 kernel IOUserSerial::call0(allocResources) ==>

par défaut 09:30:00.056118+0200 kernel IOUserSerial::call0() locklevel = 1

par défaut 09:30:00.056212+0200 kernel IOUserSerial::<private>: 527 0x600003500058

par défaut 09:30:00.056277+0200 kernel IOUserSerial::<private>: 57 0x600003500058

par défaut 09:30:00.057142+0200 kernel IOUserSerial::call0() <== 0

par défaut 09:30:00.057151+0200 kernel IOUserSerial::call0(hwProgramMCR) ==>

par défaut 2019-10-.05715325 09:30:00+0200 kernel IOUserSerial::call0() locklevel = 1

par défaut 09:30:00.057467+0200 kernel IOUserSerial::call0() <== 0

par défaut 09:30:00.057471+0200 kernel IOUserSerial::call0(hwActivate) ==>

par défaut 09:30:00.057472+0200 kernel IOUserSerial::call0() locklevel = 1

par défaut 09:30:00.057506+0200 kernel IOUserSerial::<private>: 546 0x600003500058

par défaut 09:30:00.057508+0200 kernel IOUserSerial::<private>: 117 0x600003500058

par défaut 09:30:00.058573+0200 kernel IOUserSerial::call0() <== 0

par défaut 09:30:00.058581+0200 kernel IOUserSerial::call0(hwResetFIFO) ==>

par défaut 09:30:00.058583+0200 kernel IOUserSerial::call0() locklevel = 1

On 10.15.1

par défaut 00:28:31.295445-0700 kernel IOUserSerial::call0(allocResources) ==>

par défaut 00:28:31.295501-0700 kernel IOUserSerial::call0() locklevel = 1

par défaut 00:28:31.296030-0700 kernel IOUserSerial::call0() <== e00002bf

par défaut 00:28:31.296044-0700 kernel IOUserSerial::call0(freeResources) ==>

par défaut 00:28:31.296046-0700 kernel IOUserSerial::call0() locklevel = 1

par défaut 00:28:31.296238-0700 kernel IOUserSerial::call0() <== e00002bf

0

Answer 2

inmim OP

Feb ’20

I have installed that driver, and I still do not have access to my ESP32/8266 baords. nothing shows up in my .dev either

0

	#include
	#include
	#include
	#include
	#include
	#include

	int main(int argc, char **argv) {


	char file[] = "/dev/tty.usbserial-A600QJHB";


	int fd = open(file, 0x20006, 0x0);


	if (fd == -1) {
	printf("Cannot open device %s errno %d\n", file, errno);
	return -1;
	}
	printf("success\n");

	clode(fd);
	return 0;
	}