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-rw-r--r--drivers/staging/comedi/comedidev.h2
-rw-r--r--drivers/staging/comedi/drivers.c33
-rw-r--r--drivers/staging/comedi/drivers/ni_mio_common.c10
3 files changed, 38 insertions, 7 deletions
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index dcb637665eb7..35432fbd6551 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -984,6 +984,8 @@ int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
unsigned int mask);
unsigned int comedi_dio_update_state(struct comedi_subdevice *,
unsigned int *data);
+unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,
+ struct comedi_cmd *cmd);
unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
unsigned int comedi_nscans_left(struct comedi_subdevice *s,
unsigned int nscans);
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 1736248bc5b8..8ca5493c66fe 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -390,11 +390,13 @@ unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
EXPORT_SYMBOL_GPL(comedi_dio_update_state);
/**
- * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes
+ * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in
+ * bytes
* @s: COMEDI subdevice.
+ * @cmd: COMEDI command.
*
* Determines the overall scan length according to the subdevice type and the
- * number of channels in the scan.
+ * number of channels in the scan for the specified command.
*
* For digital input, output or input/output subdevices, samples for
* multiple channels are assumed to be packed into one or more unsigned
@@ -404,9 +406,9 @@ EXPORT_SYMBOL_GPL(comedi_dio_update_state);
*
* Returns the overall scan length in bytes.
*/
-unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
+unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,
+ struct comedi_cmd *cmd)
{
- struct comedi_cmd *cmd = &s->async->cmd;
unsigned int num_samples;
unsigned int bits_per_sample;
@@ -423,6 +425,29 @@ unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
}
return comedi_samples_to_bytes(s, num_samples);
}
+EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd);
+
+/**
+ * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes
+ * @s: COMEDI subdevice.
+ *
+ * Determines the overall scan length according to the subdevice type and the
+ * number of channels in the scan for the current command.
+ *
+ * For digital input, output or input/output subdevices, samples for
+ * multiple channels are assumed to be packed into one or more unsigned
+ * short or unsigned int values according to the subdevice's %SDF_LSAMPL
+ * flag. For other types of subdevice, samples are assumed to occupy a
+ * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.
+ *
+ * Returns the overall scan length in bytes.
+ */
+unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
+{
+ struct comedi_cmd *cmd = &s->async->cmd;
+
+ return comedi_bytes_per_scan_cmd(s, cmd);
+}
EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);
static unsigned int __comedi_nscans_left(struct comedi_subdevice *s,
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index 0fa85d55c82f..fe03a41dc5cf 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -3477,6 +3477,7 @@ static int ni_cdio_check_chanlist(struct comedi_device *dev,
static int ni_cdio_cmdtest(struct comedi_device *dev,
struct comedi_subdevice *s, struct comedi_cmd *cmd)
{
+ unsigned int bytes_per_scan;
int err = 0;
int tmp;
@@ -3506,9 +3507,12 @@ static int ni_cdio_cmdtest(struct comedi_device *dev,
err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
cmd->chanlist_len);
- err |= comedi_check_trigger_arg_max(&cmd->stop_arg,
- s->async->prealloc_bufsz /
- comedi_bytes_per_scan(s));
+ bytes_per_scan = comedi_bytes_per_scan_cmd(s, cmd);
+ if (bytes_per_scan) {
+ err |= comedi_check_trigger_arg_max(&cmd->stop_arg,
+ s->async->prealloc_bufsz /
+ bytes_per_scan);
+ }
if (err)
return 3;