Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1338326

[PATCH 8/8] staging: comedi: COMEDI_BUFINFO: terminate "write" command when stopped

Show all headers | View raw

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 <abbotti@mev.co.uk>
---
 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 7cb1d06..d1cf6a1 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);
-- 
2.7.0

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

staging: comedi: COMEDI_BUFINFO: some behavioural changes Ian Abbott <abbotti@mev.co.uk> - 2016-02-19 17:20 +0100
  [PATCH 2/8] staging: comedi: COMEDI_BUFINFO: force bytes_read or bytes_written to 0 Ian Abbott <abbotti@mev.co.uk> - 2016-02-19 17:20 +0100
  [PATCH 5/8] staging: comedi: COMEDI_BUFINFO: return error if no active command Ian Abbott <abbotti@mev.co.uk> - 2016-02-19 17:20 +0100
  [PATCH 8/8] staging: comedi: COMEDI_BUFINFO: terminate "write" command when stopped Ian Abbott <abbotti@mev.co.uk> - 2016-02-19 17:20 +0100
  [PATCH 7/8] staging: comedi: COMEDI_BUFINFO: return -EPIPE for abnormal read Ian Abbott <abbotti@mev.co.uk> - 2016-02-19 17:20 +0100

csiph-web