From be611a1de3989bd03a09ae9fbfbacf19072169af Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 19 Feb 2016 16:13:57 +0000 Subject: [PATCH] staging: comedi: COMEDI_BUFINFO: terminate "write" command when stopped The `COMEDI_BUFINFO` ioctl is used to advance the current position in the buffer by a specified amount (which can be 0) and get the current position. An asynchronous command in the "read" direction is terminated automatically once it has stopped and information about the final position and error has been reported back to the user. That is not currently done for commands in the "write" direction. Change it to terminate the command in the "write" direction automatically. If the command stopped with an error, report an `EPIPE` error back to the user, otherwise just report the final buffer position back to the user. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 7cb1d06a8124..d1cf6a1c92a4 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1121,6 +1121,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, if (!async || s->busy != file) return -EINVAL; + runflags = comedi_get_subdevice_runflags(s); if (!(async->cmd.flags & CMDF_WRITE)) { /* command was set up in "read" direction */ if (bi.bytes_read) { @@ -1132,7 +1133,6 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, * {"read" position not updated or command stopped normally}, * then become non-busy. */ - runflags = comedi_get_subdevice_runflags(s); if (comedi_buf_read_n_available(s) == 0 && !comedi_is_runflags_running(runflags) && (bi.bytes_read == 0 || @@ -1144,9 +1144,12 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, bi.bytes_written = 0; } else { /* command was set up in "write" direction */ - if (!comedi_is_subdevice_running(s)) + if (!comedi_is_runflags_running(runflags)) { bi.bytes_written = 0; - if (bi.bytes_written) { + become_nonbusy = true; + if (comedi_is_runflags_in_error(runflags)) + retval = -EPIPE; + } else if (bi.bytes_written) { comedi_buf_write_alloc(s, bi.bytes_written); bi.bytes_written = comedi_buf_write_free(s, bi.bytes_written); -- 2.30.2