From 75f6108fa91bb80e9f7e8ead81f0cedf171d00a2 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Thu, 30 Oct 2014 12:42:32 +0000 Subject: [PATCH] staging: comedi: check actual data direction for COMEDI_BUFINFO ioctl `do_bufinfo_ioctl()` handled the `COMEDI_BUFINFO` ioctl. It is supposed to update the read or write positions in the buffer depending on the direction of data transfer set up by the asynchronous command. Currently it checks the `SDF_CMD_READ` and `SDF_CMD_WRITE` subdevice flags. That's fine for most subdevices - the ones that only support one direction, but is incorrect for those subdevices that allow the command to be set up in either direction. Since we now set the `CMDF_WRITE` flag according to the data transfer direction of the current command running on the subdevice, check that flag instead. Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 63afd78441f1..704ae25c5710 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -991,7 +991,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, if (s->busy != file) return -EACCES; - if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) { + if (bi.bytes_read && !(async->cmd.flags & CMDF_WRITE)) { bi.bytes_read = comedi_buf_read_alloc(s, bi.bytes_read); comedi_buf_read_free(s, bi.bytes_read); @@ -1001,7 +1001,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, } } - if (bi.bytes_written && (s->subdev_flags & SDF_CMD_WRITE)) { + if (bi.bytes_written && (async->cmd.flags & CMDF_WRITE)) { bi.bytes_written = comedi_buf_write_alloc(s, bi.bytes_written); comedi_buf_write_free(s, bi.bytes_written); -- 2.34.1