Re: problem with select() - 2.4.5
On Fri, 22 Jun 2001, Thomas Speck wrote:
>
> Hi !
> I have a problem with reading from a serial port using select() under
> 2.4.5. What I am doing is basically the following:
>
> fd_set readfds;
> struct timeval timeout;
> int s;
>
> serialfd = open("/dev/ttyS0", O_RDWR );
>
> init_serial(B9600);
>
> timeout.tv_sec = 2; /* ! */
> timeout.tv_usec = 0;
> FD_ZERO();
> FD_SET(serialfd,);
>
> s=select(serialfd+1, , NULL, NULL, );
> ...
>
> But s is always equal to 0 even when I am sure there are data to read.
> If I use
>
> s=select(serialfd+1, NULL, , NULL, );
>
> (with the corresponding initialisation of writefds) it returns s=1 and I
> can write to the serial port. I can see that since the lights of the modem
> are flashing.
> I noticed that behavior since I tried to send some "ATZ" with the
> write-function but I never got the "OK" back.
>
> However, the same programme works under 2.2.19.
Probably I should have given the init_serial() as well; So here it is:
(it is basically the one from the serial-programming-howto)
int init_serial(tcflag_t baud)
{
struct termios tio;
tcgetattr(serialfd,);
tio.c_cflag = baud | CLOCAL;
tio.c_iflag = IGNPAR;
tio.c_oflag = 0;
tio.c_lflag = 0;
tio.c_cc[VTIME] = 0;
tio.c_cc[VMIN] = 1;
tcflush(serialfd, TCIFLUSH);
tcsetattr(serialfd,TCSANOW,);
return 0;
}
Thank you for any help
--
Thomas
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
problem with select() - 2.4.5
Hi !
I have a problem with reading from a serial port using select() under
2.4.5. What I am doing is basically the following:
fd_set readfds;
struct timeval timeout;
int s;
serialfd = open("/dev/ttyS0", O_RDWR );
init_serial(B9600);
timeout.tv_sec = 2; /* ! */
timeout.tv_usec = 0;
FD_ZERO();
FD_SET(serialfd,);
s=select(serialfd+1, , NULL, NULL, );
...
But s is always equal to 0 even when I am sure there are data to read.
If I use
s=select(serialfd+1, NULL, , NULL, );
(with the corresponding initialisation of writefds) it returns s=1 and I
can write to the serial port. I can see that since the lights of the modem
are flashing.
I noticed that behavior since I tried to send some "ATZ" with the
write-function but I never got the "OK" back.
However, the same programme works under 2.2.19.
Any help, please ?
--
Thomas
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
problem with select() - 2.4.5
Hi ! I have a problem with reading from a serial port using select() under 2.4.5. What I am doing is basically the following: fd_set readfds; struct timeval timeout; int s; serialfd = open(/dev/ttyS0, O_RDWR ); init_serial(B9600); timeout.tv_sec = 2; /* ! */ timeout.tv_usec = 0; FD_ZERO(readfds); FD_SET(serialfd,readfds); s=select(serialfd+1, readfds, NULL, NULL, timeout); ... But s is always equal to 0 even when I am sure there are data to read. If I use s=select(serialfd+1, NULL, writefds, NULL, timeout); (with the corresponding initialisation of writefds) it returns s=1 and I can write to the serial port. I can see that since the lights of the modem are flashing. I noticed that behavior since I tried to send some ATZ with the write-function but I never got the OK back. However, the same programme works under 2.2.19. Any help, please ? -- Thomas - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: problem with select() - 2.4.5
On Fri, 22 Jun 2001, Thomas Speck wrote:
Hi !
I have a problem with reading from a serial port using select() under
2.4.5. What I am doing is basically the following:
fd_set readfds;
struct timeval timeout;
int s;
serialfd = open(/dev/ttyS0, O_RDWR );
init_serial(B9600);
timeout.tv_sec = 2; /* ! */
timeout.tv_usec = 0;
FD_ZERO(readfds);
FD_SET(serialfd,readfds);
s=select(serialfd+1, readfds, NULL, NULL, timeout);
...
But s is always equal to 0 even when I am sure there are data to read.
If I use
s=select(serialfd+1, NULL, writefds, NULL, timeout);
(with the corresponding initialisation of writefds) it returns s=1 and I
can write to the serial port. I can see that since the lights of the modem
are flashing.
I noticed that behavior since I tried to send some ATZ with the
write-function but I never got the OK back.
However, the same programme works under 2.2.19.
Probably I should have given the init_serial() as well; So here it is:
(it is basically the one from the serial-programming-howto)
int init_serial(tcflag_t baud)
{
struct termios tio;
tcgetattr(serialfd,tio);
tio.c_cflag = baud | CLOCAL;
tio.c_iflag = IGNPAR;
tio.c_oflag = 0;
tio.c_lflag = 0;
tio.c_cc[VTIME] = 0;
tio.c_cc[VMIN] = 1;
tcflush(serialfd, TCIFLUSH);
tcsetattr(serialfd,TCSANOW,tio);
return 0;
}
Thank you for any help
--
Thomas
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: temperature standard - global config option?
On Thu, 7 Jun 2001, Michael H. Warfield wrote: > A "population inversion" (a condition where the energized states > are more likely to be populated than the ground states) is at the heart > of many things we take for granted today such as lasers, masers, leds, > NMR (Nuclear Magnetic Resonance) and MRI (the medical use of NMR). > > Those "population inversions" represents an "energized state" > that is more energetic than the state that would be present in a steady > state infinite temperature. > > Mathematically, those states can actually be treated as negative > absolute temperatures. IOW, negative absolute temperatures are actually > hotter than infinite. > > It's true that these are not STEADY STATE conditions or in > equilibrium (which is how we take advantage of populations inversions - > by their actions in returning to equilibrium), but the math still works. > Just check out a few issues of Scientific American from the mid 1970's > on "Negative Absolute Temperatures in Nuclear Magnetic Resonance" and > to the scientific journals they reference. I won an argument with > a physics prof (PhD in high energy physics) over that very issue when > I did the same thing in a 400 level senior level physics lab on NMR back > then. It's actually pretty damn simple, once you work the math, and it > agravated him that he didn't believe it but couldn't argue with the math > till he saw the work and publication from someone else. Then he conceeded > that I had him and I had been right. Nobody is doubting that population inversions do exist. And you also can do all kind of mathematics with it if you like and even calculate a temperature. But I think you shouldn't interprete this kind of temperature as something that is macroscopically existant or even measurable. You also wouldn't say quantum wave functions do exist, would you ? > IAC... Negative absolute temperatures are about as meaningless > to this particular discussion as is expressing the temperature in 1/100s > of a Kelvin which would have a precision than exceeds the accuracy of > the measuring chips by two orders of magnitude. IOW... Both are silly > and meaningless to this case. One is out of range in magnitude and one > is out of the range of accuracy. I agree and I think we shouldn't get too out of topic ... -- Thomas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: temperature standard - global config option?
On Thu, 7 Jun 2001, Michael H. Warfield wrote: A population inversion (a condition where the energized states are more likely to be populated than the ground states) is at the heart of many things we take for granted today such as lasers, masers, leds, NMR (Nuclear Magnetic Resonance) and MRI (the medical use of NMR). Those population inversions represents an energized state that is more energetic than the state that would be present in a steady state infinite temperature. Mathematically, those states can actually be treated as negative absolute temperatures. IOW, negative absolute temperatures are actually hotter than infinite. It's true that these are not STEADY STATE conditions or in equilibrium (which is how we take advantage of populations inversions - by their actions in returning to equilibrium), but the math still works. Just check out a few issues of Scientific American from the mid 1970's on Negative Absolute Temperatures in Nuclear Magnetic Resonance and to the scientific journals they reference. I won an argument with a physics prof (PhD in high energy physics) over that very issue when I did the same thing in a 400 level senior level physics lab on NMR back then. It's actually pretty damn simple, once you work the math, and it agravated him that he didn't believe it but couldn't argue with the math till he saw the work and publication from someone else. Then he conceeded that I had him and I had been right. Nobody is doubting that population inversions do exist. And you also can do all kind of mathematics with it if you like and even calculate a temperature. But I think you shouldn't interprete this kind of temperature as something that is macroscopically existant or even measurable. You also wouldn't say quantum wave functions do exist, would you ? IAC... Negative absolute temperatures are about as meaningless to this particular discussion as is expressing the temperature in 1/100s of a Kelvin which would have a precision than exceeds the accuracy of the measuring chips by two orders of magnitude. IOW... Both are silly and meaningless to this case. One is out of range in magnitude and one is out of the range of accuracy. I agree and I think we shouldn't get too out of topic ... -- Thomas - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
ov511 problem
Hi I am trying to get working a Spacec@m 300 (USB) by Trust. I tried this under 2.2.18 and 2.4.3. In order to get the camera detected I can use the usb-uhci or uhci module (the result is the same). The camera gets detected (some OV7610 gets probed - I don't know if this is the correct one) and after loading the ov511 module I get the picture of the camera displayed with xawt-3.38 (resolution 640x480 - the camera is able to this). The problem I am running into is that the framerate is extremely slow (maybe 3 fps), however, from the specifications it should work with 30 fps. My system is a Pentium II with 300 Mhz. Some Miro TV card with a BT848 chip works fine with the bttv driver. Do you have any idea ? If you need more info, just let me know. I am also willing to do some tests... -- Thomas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
ov511 problem
Hi I am trying to get working a Spacec@m 300 (USB) by Trust. I tried this under 2.2.18 and 2.4.3. In order to get the camera detected I can use the usb-uhci or uhci module (the result is the same). The camera gets detected (some OV7610 gets probed - I don't know if this is the correct one) and after loading the ov511 module I get the picture of the camera displayed with xawt-3.38 (resolution 640x480 - the camera is able to this). The problem I am running into is that the framerate is extremely slow (maybe 3 fps), however, from the specifications it should work with 30 fps. My system is a Pentium II with 300 Mhz. Some Miro TV card with a BT848 chip works fine with the bttv driver. Do you have any idea ? If you need more info, just let me know. I am also willing to do some tests... -- Thomas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Where is the RAM?
On Thu, 22 Mar 2001, Neal Gieselman wrote: > I have a Redhat 6.1 WS that was installed with 64 MB RAM. I added another > 64 MB, booted, BIOS sees it, but top, free, etc still see only 64 MB. > Any clues on what to do? Maybe append="mem=128M" in lilo.conf helps ... -- Thomas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Where is the RAM?
On Thu, 22 Mar 2001, Neal Gieselman wrote: I have a Redhat 6.1 WS that was installed with 64 MB RAM. I added another 64 MB, booted, BIOS sees it, but top, free, etc still see only 64 MB. Any clues on what to do? Maybe append="mem=128M" in lilo.conf helps ... -- Thomas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
