FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2025-02-01 16:44:26 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Staging: comedi: don't write to buffer if command finished

Browse Source 
For write(), any data copied to the data buffer after the previously
set up streaming acquisition command has finished won't be used, but a
non-empty write() does not currently return 0 (or -EPIPE on error) after
the command has finished until the data buffer has been filled up.
Change this behavior to return 0 (or -EPIPE) any time after the command
has finished, without bothering to fill up the buffer with more useless
data.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Ian Abbott 2010-05-19 17:22:41 +01:00 committed by Greg Kroah-Hartman
parent ee4063fa6b
commit d261154057
1 changed files with 13 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/staging/comedi/comedi_fops.c
View File

@ -1576,6 +1576,19 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
while (nbytes > 0 && !retval) {
set_current_state(TASK_INTERRUPTIBLE);
if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
if (count == 0) {
if (comedi_get_subdevice_runflags(s) &
SRF_ERROR) {
retval = -EPIPE;
} else {
retval = 0;
}
do_become_nonbusy(dev, s);
}
break;
}
n = nbytes;
m = n;
@ -1588,16 +1601,6 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
n = m;
if (n == 0) {
if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
if (comedi_get_subdevice_runflags(s) &
SRF_ERROR) {
retval = -EPIPE;
} else {
retval = 0;
}
do_become_nonbusy(dev, s);
break;
}
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;