On 04/11/14 16:50, H Hartley Sweeten wrote:
Introduce a new member to comedi_async to count the number of scans completed.
This member is cleared by comedi_buf_reset() along with the other comedi_async
members. It is incremented in comedi_inc_scan_progress() when the end of scan
is detected.
This member will be used to clean up the scan counting in the comedi drivers.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/comedi_buf.c | 1 +
drivers/staging/comedi/comedidev.h | 2 ++
drivers/staging/comedi/drivers.c | 1 +
3 files changed, 4 insertions(+)
diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index eb3fecf..19e7b22 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -236,6 +236,7 @@ void comedi_buf_reset(struct comedi_subdevice *s)
async->buf_read_ptr = 0;
async->cur_chan = 0;
+ async->scans_done = 0;
async->scan_progress = 0;
async->munge_chan = 0;
async->munge_count = 0;
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 90af11a..bff5a58 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -121,6 +121,7 @@ struct comedi_buf_map {
* @buf_read_ptr: buffer position for reader
* @cur_chan: current position in chanlist for scan (for those
* drivers that use it)
+ * @scans_done: the number of scans completed (COMEDI_CB_EOS)
* @scan_progress: amount received or sent for current scan (in bytes)
* @munge_chan: current position in chanlist for "munging"
* @munge_count: "munge" count (in bytes, modulo 2**32)
@@ -201,6 +202,7 @@ struct comedi_async {
unsigned int buf_write_ptr;
unsigned int buf_read_ptr;
unsigned int cur_chan;
+ unsigned int scans_done;
unsigned int scan_progress;
unsigned int munge_chan;
unsigned int munge_count;
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 9a8c5fc..4fc992b 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -352,6 +352,7 @@ void comedi_inc_scan_progress(struct comedi_subdevice *s,
async->scan_progress += num_bytes;
if (async->scan_progress >= scan_length) {
+ async->scans_done += async->scan_progress / scan_length;
async->scan_progress %= scan_length;
async->events |= COMEDI_CB_EOS;
}
The patch is fine, but as a follow-up patch, async->scans_done could be
clamped to UINT_MAX (or possibly async->cmd.stop_arg, but UINT_MAX is
easier), e.g.:
unsigned int scans = async->scan_progress / scan_length;
if (async->scans_done < UINT_MAX - scans)
async->scans_done += scans;
else
async->scans_done = UINT_MAX;
async->scan_progress -= scans * scan_length;
async->events |= COMEDI_CB_EOS;
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Web: http://www.mev.co.uk/ )=-
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