linux hangs after device unplugged from serial port
I have a raspberry pi with custom linux built using buildroot and USB modem to connect to the internet.
I am using python script to obtain CSQ when using internet.
To do this, I am open /dev/ttyUSB2 (PCUI port of modem) with hardware flow control flags set:
serial.Serial(self.address, baudrate=125200, timeout=1, rtscts=True, dsrdtr=True)
Unfortunately, port opens only when rtscts and dsrdtr flags set to true.
Further when I am hot-unplug modem without closing port - linux hangs and I receive messages in console like that:
mmc0: timeout waiting for hardware interrupt
INFO: rcu_sched detected stalls on CPU/tasks:
o0-...: (a GPs behind) idle=d93/2/0 softirq=9708/9709 fqs=84
o(detected by 2, t=2102 jiffies, g=5874, c=5873, q=559)
Hope someone will help me because I don't know where i should find the answer)
linux usb python
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
add a comment |
I have a raspberry pi with custom linux built using buildroot and USB modem to connect to the internet.
I am using python script to obtain CSQ when using internet.
To do this, I am open /dev/ttyUSB2 (PCUI port of modem) with hardware flow control flags set:
serial.Serial(self.address, baudrate=125200, timeout=1, rtscts=True, dsrdtr=True)
Unfortunately, port opens only when rtscts and dsrdtr flags set to true.
Further when I am hot-unplug modem without closing port - linux hangs and I receive messages in console like that:
mmc0: timeout waiting for hardware interrupt
INFO: rcu_sched detected stalls on CPU/tasks:
o0-...: (a GPs behind) idle=d93/2/0 softirq=9708/9709 fqs=84
o(detected by 2, t=2102 jiffies, g=5874, c=5873, q=559)
Hope someone will help me because I don't know where i should find the answer)
linux usb python
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
1
The Unix system call interfaces in the C programming language have option flagsO_NDELAYandO_NONBLOCK. If Python has something analogous, that might solve your problem of the open hanging until the control lines are true.
– Scott
Dec 24 '18 at 0:42
add a comment |
I have a raspberry pi with custom linux built using buildroot and USB modem to connect to the internet.
I am using python script to obtain CSQ when using internet.
To do this, I am open /dev/ttyUSB2 (PCUI port of modem) with hardware flow control flags set:
serial.Serial(self.address, baudrate=125200, timeout=1, rtscts=True, dsrdtr=True)
Unfortunately, port opens only when rtscts and dsrdtr flags set to true.
Further when I am hot-unplug modem without closing port - linux hangs and I receive messages in console like that:
mmc0: timeout waiting for hardware interrupt
INFO: rcu_sched detected stalls on CPU/tasks:
o0-...: (a GPs behind) idle=d93/2/0 softirq=9708/9709 fqs=84
o(detected by 2, t=2102 jiffies, g=5874, c=5873, q=559)
Hope someone will help me because I don't know where i should find the answer)
linux usb python
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
I have a raspberry pi with custom linux built using buildroot and USB modem to connect to the internet.
I am using python script to obtain CSQ when using internet.
To do this, I am open /dev/ttyUSB2 (PCUI port of modem) with hardware flow control flags set:
serial.Serial(self.address, baudrate=125200, timeout=1, rtscts=True, dsrdtr=True)
Unfortunately, port opens only when rtscts and dsrdtr flags set to true.
Further when I am hot-unplug modem without closing port - linux hangs and I receive messages in console like that:
mmc0: timeout waiting for hardware interrupt
INFO: rcu_sched detected stalls on CPU/tasks:
o0-...: (a GPs behind) idle=d93/2/0 softirq=9708/9709 fqs=84
o(detected by 2, t=2102 jiffies, g=5874, c=5873, q=559)
Hope someone will help me because I don't know where i should find the answer)
linux usb python
linux usb python
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
asked Dec 23 '18 at 22:02
Paul GolubevPaul Golubev
1
1
1
The Unix system call interfaces in the C programming language have option flagsO_NDELAYandO_NONBLOCK. If Python has something analogous, that might solve your problem of the open hanging until the control lines are true.
– Scott
Dec 24 '18 at 0:42
add a comment |
1
The Unix system call interfaces in the C programming language have option flagsO_NDELAYandO_NONBLOCK. If Python has something analogous, that might solve your problem of the open hanging until the control lines are true.
– Scott
Dec 24 '18 at 0:42
1
1
The Unix system call interfaces in the C programming language have option flags
O_NDELAY and O_NONBLOCK. If Python has something analogous, that might solve your problem of the open hanging until the control lines are true.– Scott
Dec 24 '18 at 0:42
The Unix system call interfaces in the C programming language have option flags
O_NDELAY and O_NONBLOCK. If Python has something analogous, that might solve your problem of the open hanging until the control lines are true.– Scott
Dec 24 '18 at 0:42
add a comment |
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1
The Unix system call interfaces in the C programming language have option flags
O_NDELAYandO_NONBLOCK. If Python has something analogous, that might solve your problem of the open hanging until the control lines are true.– Scott
Dec 24 '18 at 0:42