From: Ian Abbott Date: Fri, 19 Feb 2016 16:13:55 +0000 (+0000) Subject: staging: comedi: COMEDI_BUFINFO: become non-busy even if bytes_read is 0 X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=f3aa8c0becfb1d968e552721cc1be8b91032539b;p=deliverable%2Flinux.git staging: comedi: COMEDI_BUFINFO: become non-busy even if bytes_read is 0 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 new position. On input, the `bytes_read` member of `struct comedi_bufinfo` specified the amount to advance the "read" position for an asynchronous command in the "read" direction. If the command has already stopped normally, and the "read" position has been advanced to the end of all available data, the command is terminated by calling `do_become_nonbusy()`. (That is not currently done if the command stopped with an error.) Currently, the command is only terminated if the user is trying to advance the "read" position by a non-zero amount. Change it to allow the command to be terminated even if the user is not trying to advance the "read" position. This is justifiable, as the only time a command stops without error is when it has been set up to read a finite amount of data. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index a9fabf7a1000..ffe58208869e 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1131,11 +1131,10 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, if (bi.bytes_read) { comedi_buf_read_alloc(s, bi.bytes_read); bi.bytes_read = comedi_buf_read_free(s, bi.bytes_read); - - if (comedi_is_subdevice_idle(s) && - comedi_buf_read_n_available(s) == 0) - become_nonbusy = true; } + if (comedi_is_subdevice_idle(s) && + comedi_buf_read_n_available(s) == 0) + become_nonbusy = true; bi.bytes_written = 0; } else { /* command was set up in "write" direction */