Re: usbtmc makes Rigol DS1052E oscilloscope crash
Mark Whitis
> I'm experiencing trouble connecting to a Rigol DS1052E oscilloscope via
> the usbtmc USB class driver. When requesting small amounts of data it
> works quite nicely, but when requesting a large chunk (i.e. when
> requesting the whole memory to be transferred), the read aborts, the
> connection times out and ultimately this leads to the oscilloscope
> crashing.
On my system, I have a similar problem but with somewhat different
symptoms.
I only get 2018 bytes back, whether the scope sends 8192 or
524288 bytes. 610 bytes and 1210 bytes read ok.
In the source for this module, I notice that there is a 2048 byte buffer
and a 10ms timeout, either of which could cause trouble depending on how
they are used.
Linux cervantes 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:58:03 UTC
2009 x86_64 GNU/Linux
/rigolterm
Rigol Technologies,DS1052E,DS1ED122307041,00.02.04.00.01
Rigol Technologies,DS1052E,DS1ED122307041,00.02.04.00.01
rigol> *IDN?
[56]:Rigol Technologies,DS1052E,DS1ED122307041,00.02.04.00.01
rigol> :ACQUIRE:MEMDEPTH LONG
No response
[-1]:
rigol> :WAVFORM:POINTS:MODE RAW
No response
[-1]:
rigol> :RUN
No response
[-1]:
rigol> :FORCE
No response
[-1]:
rigol> :STOP
No response
[-1]:
rigol> :CHAN1:MEMD?
No response
[-1]:
rigol> :CHAN1:MEMD?
No response
[-1]:
rigol> :CHAN1:MEMD?
No response
[-1]:
rigol> :CHAN1:MEMD?
No response
[-1]:
rigol> :CHAN1:MEMD?
[6]:524288
rigol> :WAV:DATA? CHANNEL1
No response
[-1]:
rigol> :WAV:DATA? CHANNEL1
No response
[-1]:
rigol> :WAV:DATA? CHANNEL1
[2018]:
23 38 30 30 35 32 34 32 38 38 CA CA CA CA CA CA
CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA
CA C9 CA C9 CA C9 CA CA C9 CA CA CA CA C9 C9 CA
CA C9 C9 C9 C9 C9 CA CA C9 CA CA CA C9 C9 C9 C9
C9 CA CA CA CA C9 CA CA C9 CA CA CA CA C9 CA C9
CA C9 CA CA CA CA C9 C9 C9 CA CA C9 C9 CA C9 CA
CA C9 CA CA CA CA C9 CA CA CA CA CA CA C9 CA C9
CA C9 C9 C9 C9 CA CA C9 C9 CA CA CA CA CA C9 C9
CA CA CA C9 CA C9 CA C9 CA C9 C9 CA C9 CA CA C9
C9 CA C9 CA C9 C9 C9 CA C9 CA CA C9 C9 CA CA CA
C9 C9 C9 CA CA CA CA CA CA CA C9 C9 C9 CA C9 C9
C9 C9 CA CA C9 C9 C9 CA C9 CA C9 C9 CA C9 CA CA
C9 C9 CA CA C9 C9 CA CA CA C9 CA C9 CA CA CA CA
C9 C9 CA CA CA CA CA CA C9 CA C9 CA C9 CA CA C9
C9 CA CA CA CA CA C9 CA C9 C9 CA CA C9 C9 CA CA
CA CA C9 C9 C9 CA C9 CA C9 C9 C9 CA CA C9 C9 C9
C9 C9 CA CA CA CA C9 C9 CA C9 C9 C9 C9 C9 CA C9
CA C9 C9 CA CA CA CA C9 CA CA CA CA C9 CA CA CA
C9 C9 CA C9 C9 CA C9 CA CA CA C9 C9 CA C9 CA CA
CA CA C9 CA CA C9 C9 C9 C9 C9 C9 CA CA CA C9 C9
C9 CA CA C9 CA C9 CA C9 C9 C9 C9 C9 C9 CA C9 CA
C9 C9 CA C9 C9 C9 CA CA C9 CA CA CA CA CA CA CA
C9 C9 C9 C9 C9 CA CA CA CA C9 C9 C9 CA CA CA CA
C9 C9 C9 C9 C9 CA CA CA CA CA CA C9 CA C9 C9 C9
CA CA CA CA C9 CA CA CA C9 CA C9 C9 C9 C9 C9 C9
C9 CA C9 CA C9 CA C9 C9 C9 CA CA CA CA CA CA CA
C9 C9 C9 C9 C9 C9 CA C9 C9 C9 C9 CA CA CA CA CA
C9 C9 C9 C9 CA CA CA CA CA CA CA C9 CA CA CA C9
CA CA C9 CA C9 C9 C9 CA CA C9 CA CA C9 CA C9 CA
CA CA CA C9 C9 CA C9 CA CA C9 C9 CA CA CA CA CA
CA CA CA CA C9 CA C9 CA CA CA CA CA CA CA CA CA
CA C9 CA CA CA CA CA CA C9 C9 CA C9 CA C9 C9 CA
CA C9 C9 CA C9 CA CA CA C9 C9 CA C9 C9 CA CA CA
CA CA C9 CA CA CA CA C9 C9 C9 CA CA C9 C9 CA CA
CA CA CA C9 C9 C9 C9 CA CA C9 C9 C9 C9 C9 CA C9
C9 C9 CA CA CA CA CA CA CA CA C9 CA CA CA C9 C9
CA CA C9 CA CA CA CA CA CA C9 C9 CA CA C9 CA CA
CA CA C9 CA C9 C9 CA CA C9 CA C9 CA CA CA C9 C9
CA CA C9 CA CA CA C9 C9 C9 CA C9 C9 CA C9 CA CA
C9 CA C9 CA CA C9 C9 CA C9 CA C9 CA CA CA CA C9
C9 C9 CA CA CA CA CA CA CA CA CA CA CA CA CA CA
CA CA CA CA C9 CA CA CA CA C9 CA CA CA C9 CA C9
CA C9 C9 CA C9 CA CA CA CA C9 CA C9 CA CA CA CA
CA CA CA C9 CA CA CA C9 C9 C9 C9 C9 CA CA CA C9
CA C9 CA C9 C9 CA CA CA C9 C9 CA CA C9 C9 C9 C9
CA CA CA CA CA CA CA CA CA C9 C9 CA C9 C9 C9 C9
CA CA CA C9 C9 C9 CA CA CA CA CA CA CA CA CA C9
CA C9 C9 CA CA C9 C9 CA CA CA CA CA CA CA CA C9
C9 C9 C9 C9 C9 CA C9 CA C9 C9 CA CA C9 C9 C9 CA
CA CA CA C9 C9 CA CA C9 C9 CA CA C9 C9 C9 CA CA
CA CA C9 CA C9 CA C9 C9 C9 CA CA C9 CA C9 C9 CA
CA C9 C9 C9 CA CA C9 CA C9 CA C9 C9 C9 C9 CA CA
C9 C9 C9 CA CA CA C9 CA C9 CA CA C9 C9 C9 C9 CA
C9 CA CA C9 CA C9 CA C9 C9 C9 CA CA C9 C9 C9 CA
CA CA C9 C9 CA CA CA C9 C9 CA CA CA C9 C9 C9 C9
C9 C9 C9 CA C9 C9 CA CA CA CA C9 CA C9 CA CA C9
C9 CA CA CA C9 C9 CA C9 CA CA CA CA C9 CA C9 CA
C9 CA CA C9 C9 C9 C9 C9 C9 CA CA CA C9 C9 C9 C9
C9 C9 CA C9 C9 CA C9 CA CA CA C9 C9 CA CA C9 CA
C9 CA C9 C9 C9 C9 CA C9 C9 CA C9 C9 C9 CA CA C9
C9 CA CA C9 C9 CA CA CA C9 C9 C9 CA C9 C9 CA C9
C9 CA CA C9 C9 C9 CA CA CA C9 C9 C9 CA C9 C9 C9
CA C9 C9 CA C9 C9 C9 CA C9 C9 C9 C9 C9 C9 CA CA
C9 C9 C9 C9 CA C9 C9 C9 C9 C9 C9 CA CA CA C9 CA
CA CA C9 C9 C9 C9 CA C9 CA CA C9 C9 C9 C9 C9 C9
CA CA C9 C9 CA CA C9 C9 C9 C9 CA C9 C9 CA CA C9
C9 C9 C9 CA CA C9 C9 C9 CA C9 C9 C9 C9 CA C9 C9
C9 C9 CA C9 C9 C9 C9 CA C9 C9 CA C9 C9 C9 C9 C9
CA C9 C9 C9 C9 C9 C9 CA CA CA C9 C9 CA CA CA CA
CA C9 C9 C9 C9 CA C9 C9 C9 C9 C9 CA C9 C9 C9 CA
C9 CA C9 CA CA C9 CA CA C9 C9 CA C9 C9 CA C9 C9
C9 C9 CA CA C9 C9 C9 C9 CA C9 C9 CA CA CA C9 C9
CA C9 C9 CA C9 C9 CA C9 C9 CA CA C9 C9 C9 C9 CA
CA CA C9 CA C9 C9 CA CA CA C9 CA CA C9 CA CA C9
C9 C9 C9 CA C9 C9 CA C9 C9 C9 C9 C9 CA CA CA CA
C9 CA CA CA C9 C9 C9 C9 CA C9 CA C9 C9 C9 C9 C9
CA CA C9 C9 C9 CA C9 CA CA C9 C9 CA CA C9 C9 C9
C9 C9 C9 C9 C9 C9 CA CA C9 C9 C9 C9 CA C9 C9 CA
CA C9 C9 C9 C9 C9 CA C9 CA CA C9 C9 C9 C9 C9 C9
CA C9 CA C9 C9 C9 C9 C9 C9 CA CA C9 C9 C9 C9 C9
CA CA C9 CA CA C9 C9 C9 C9 C9 CA C9 CA C9 C9 C9
C9 CA CA CA C9 C9 C9 C9 CA CA CA CA C9 CA C9 C9
C9 C9 CA C9 CA C9 C9 CA C9 C9 CA C9 CA CA C9 C9
CA CA CA CA C9 C9 CA C9 C9 C9 CA C9 C9 C9 C9 C9
CA CA C9 C9 C9 CA CA C9 C9 C9 C9 CA C9 CA C9 C9
CA CA C9 CA C9 CA CA C9 C9 C9 CA C9 C9 CA C9 C9
C9 C9 C9 C9 C9 CA C9 C9 C9 CA CA CA C9 C9 CA C9
C9 C9 CA CA C9 CA CA C9 CA C9 C9 CA C9 CA C9 CA
C9 C9 C9 C9 CA C9 C9 CA C9 CA C9 C9 C9 C9 CA C9
CA C9 CA C9 CA C9 C9 C9 C9 CA C9 C9 C9 C9 C9 C9
C9 C9 C9 C9 C9 C9 C9 C9 C9 C9 C9 C9 C9 CA C9 C9
CA C9 C9 C9 CA CA C9 CA CA C9 C9 CA C9 C9 CA CA
C9 C9 CA CA C9 C9 C9 C9 CA C9 C9 CA CA C9 CA C9
C9 C9 CA CA C9 C9 C9 C9 C9 CA C9 C9 C9 CA CA CA
C9 C9 CA CA C9 CA CA C9 C9 CA C9 CA C9 C9 CA C9
C9 C9 CA C9 CA C9 C9 C9 C9 C9 CA C9 C9 C9 C9 C9
C9 C9 C9 C9 C9 C9 C9 C9 C9 CA CA C9 C9 C9 CA C9
C9 CA C9 C9 CA C9 C9 C9 C9 C9 C9 C9 C9 C9 C9 C9
CA C9 C9 CA C9 C9 CA CA C9 C9 CA C9 C9 C9 C9 C9
CA C9 CA C9 C9 C9 C9 C9 C9 CA C9 C9 C9 C9 CA CA
C9 CA C9 C9 C9 CA C9 C9 CA CA C9 C9 C9 C9 CA C9
C9 CA C9 C9 C9 C9 CA CA C9 C9 C9 C9 CA C9 C9 CA
C9 C9 C9 C9 C9 C9 C9 CA CA C9 C9 CA C9 CA CA C9
C9 C9 C9 C9 C9 CA C9 C9 CA C9 C9 C9 CA CA C9 C9
C9 C9 CA C9 CA CA C9 CA CA C9 C9 CA C9 CA CA CA
CA CA CA C9 C9 C9 C9 C9 CA C9 C9 CA C9 C9 C9 C9
C9 C9 C9 C9 CA CA CA C9 C9 CA C9 C9 CA C9 CA C9
C9 CA C9 CA C9 CA C9 C9 C9 C9 CA C9 CA CA CA C9
C9 C9 C9 C9 C9 CA CA CA C9 C9 C9 C9 C9 CA C9 C9
C9 C9 CA CA C9 CA C9 CA C9 C9 CA C9 CA C9 C9 C9
C9 C9 C9 CA C9 CA C9 C9 CA C9 CA C9 C9 CA C9 CA
C9 CA C9 CA C9 C9 CA C9 CA CA CA C9 CA C9 CA C9
C9 C9 C9 C9 CA CA C9 C9 C9 C9 C9 C9 CA CA C9 C9
CA CA CA C9 C9 CA CA CA CA C9 CA CA C9 CA CA CA
C9 CA C9 C9 C9 C9 C9 CA C9 C9 CA CA CA C9 C9 C9
CA CA C9 CA C9 C9 C9 CA CA CA C9 CA C9 C9 CA C9
C9 C9 CA C9 C9 C9 C9 C9 CA CA C9 C9 CA C9 C9 C9
C9 C9 C9 C9 C9 C9 CA CA C9 C9 C9 CA CA C9 C9 CA
CA C9 C9 C9 C9 CA C9 CA C9 C9 CA C9 CA C9 C9 C9
C9 C9 C9 C9 CA C9 CA C9 C9 CA CA C9 C9 CA CA CA
C9 CA CA CA C9 CA CA CA C9 CA C9 C9 CA CA C9 CA
CA CA C9 C9 CA CA C9 C9 CA C9 C9 CA CA C9 C9 C9
C9 C9 C9 CA C9 CA C9 C9 CA CA C9 C9 C9 C9 CA C9
CA CA C9 C9 C9 C9 CA CA C9 C9 CA C9 CA C9 C9 CA
CA CA C9 CA CA CA C9 C9 C9 CA CA C9 CA C9 C9 C9
CA C9 C9 C9 CA C9 C9 C9 C9 C9 C9 C9 CA CA C9 C9
C9 CA
rigol>
rigol> :WAVE:DATA? CHANNEL1
No response
[-1]:
rigol> :WAVE:DATA? CHANNEL1
No response
[-1]:
rigol> *IDN?
No response
[-1]:
rigol> *IDN?
No response
[-1]:
rigol> *IDN?
[56]:Rigol Technologies,DS1052E,DS1ED122307041,00.02.04.00.01
rigol> :WAV:DATA? CHANNEL1
[2018]:
23 38 30 30 35 32 34 32 38 38 CA CA CA CA CA CA
CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA
CA C9 CA C9 CA C9 CA CA C9 CA CA CA CA C9 C9 CA
..
Bytes 2-9 (starting at 0) in the response are the length of the following
data in ASCII digits: 00524288. Some flakyness on intermittently responding
to commands is also evident. This seems to happen after a big data
transfer.
Intermittent response to commands continues if the program is exited and
restarted or the scope power cycled. Even after removing and reloading
the kernel module.
// rigolterm.c - Copyright 2010 by Mark Whitis
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <linux/usb/tmc.h>
char *new_fgets(char *s, int size, FILE *stream)
{
char *rc;
int i;
s[0]=0;
rc=fgets(s,size,stream);
// remove newline
for(i=0;i<size;i++) {
if(s[i]==0) break;
if(s[i]=='\n') s[i]=0;
}
// make sure string is terminated
s[size-1]=0;
return(rc);
}
int rigol_write(int handle, unsigned char *string)
{
int rc;
unsigned char buf[256];
strncpy(buf,string,sizeof(buf));
buf[sizeof(buf)-1]=0;
strncat(buf,"\n",sizeof(buf));
buf[sizeof(buf)-1]=0;
//printf("rigol_write(): \"%s\"\n",buf);
rc=write(handle, buf, strlen(buf));
if(rc<0) perror("write error");
return(rc);
}
int rigol_read(int handle, unsigned char *buf, size_t size)
{
int rc;
if(!size) return(-1);
buf[0]=0;
rc=read(handle, buf, size);
if((rc>0) && (rc<size)) buf[rc]=0;
if(rc<0) {
if(errno==ETIMEDOUT) {
printf("No response\n");
} else {
perror("read error");
}
}
// printf("rc=%d\n",rc);
return(rc);
}
const max_response_length=2097152;
const max_command_length=128;
main()
{
int handle;
int rc;
int i;
unsigned char buf[max_response_length];
unsigned char cmd[max_command_length];
handle=open("/dev/usbtmc0", O_RDWR);
if(handle<0) {
perror("error opening device");
exit(1);
}
rigol_write(handle, "*IDN?");
rigol_read(handle, buf, sizeof(buf));
printf("%s\n", buf);
rigol_write(handle, "*IDN?");
rigol_read(handle, buf, sizeof(buf));
printf("%s\n", buf);
while(1) {
printf("rigol> ");
new_fgets(cmd,sizeof(cmd),stdin);
rigol_write(handle, cmd);
rc=rigol_read(handle, buf,sizeof(buf));
if(rc<256) {
// Assume text
printf("[%d]:%s\n", rc,buf);
} else {
printf("[%d]:\n",rc);
for(i=0;i<rc;i++) {
printf("%02X ",buf[i]);
if( (i%16)==15 ) printf("\n");
}
printf("\n");
}
}
}
Previous poster probivided packet captures and debugging output:
http://www.gossamer-threads.com/lists/linux/kernel/1230111?do=post_view_threaded
One note: when you send usb commands to the scope, it locks out the front
panel. You need to use :KEY:LOCK DISABLE to unlock it (repeatedly, as
subsequent commands will lock it again). This could make the scope
appear crashed when it isn't. The letters "Rmt" appear in the upper
right corner of the screen when the front panel is locked out.
For now, I think I will try the libusb route. The kernel driver has too
many bugs and isn't portable across OSes.
The usbtmc kernel driver, when loaded, interferes with communicating with
the device via libusb even if no programs have the device open. It fails
to release the device when not in use. This is a serious problem.
Different software talking to the same device may use a mix of kernel
driver and libusb drivers. Worse, you may have one piece of software
which uses the kernel driver to talk to one device and another piece of
software which uses libusb to talk to another device, concurrently. In
that case, you can not rmmod the kernel driver as that would prevent the
first device from working.
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Mark Whitis
On Thu, 29 Jul 2010, Mark Whitis wrote:
> On my system, I have a similar problem but with somewhat different symptoms.
>
> I only get 2018 bytes back, whether the scope sends 8192 or 524288 bytes.
> 610 bytes and 1210 bytes read ok.
>
> ...
Another data point:
The author of one libusb based driver for this scope, after corresponding
with rigol, found it necessary to limit the first usb read from the bulk
endpoint to 64 bytes. After that continuation requests were allowed to
be full size. It is possible this is what is causing the symptoms,
though it is a bit odd that the error doesn't show up until 2K later.
If this is the source of the problem (and if it isn't, it is apparently
still the source of other problems), it could be worked around by having
an IOCTL to limit the size of the first low level read and to optionally
limit the sizes of other reads This can't be fixed at the application level by changing the size passed to read()
because of the nature of the usbtmc api in which read() returns entire
messages rather than being stream oriented.
The DS1052E uses the same firmware as some other models. The company
makes other test equipment that may share the offending code and knockoffs
of older models are sold under a couple brand names. Thus the number of
devices which might be affected could be in the dozens. Other unrelated
devices may also have similar problems with USBs very limiting timing
constraints. The DS1052E, in particular, is popular with linux users
due to its price/performance ratio, its hackability, and the fact that
more technical info and discussion has been posted on forums than for
other DSOs. Thus, incorporating some defensive programming into the
usbtmc driver would seem warranted.