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staging: comedi: adv_pci1710: Fix endian problem for AI command data 

The analog input subdevice supports Comedi asynchronous commands that
use Comedi's 16-bit sample format.  However, the calls to
`comedi_buf_write_samples()` are passing the address of a 32-bit integer
variable.  On bigendian machines, this will copy 2 bytes from the wrong
end of the 32-bit value.  Fix it by changing the type of the variables
holding the sample value to `unsigned short`.  The type of the `val`
parameter of `pci1710_ai_read_sample()` is changed to `unsigned short *`
accordingly.  The type of the `val` variable in `pci1710_ai_insn_read()`
is also changed to `unsigned short` since its address is passed to
`pci1710_ai_read_sample()`.

Fixes: a9c3a015c1 ("staging: comedi: adv_pci1710: use comedi_buf_write_samples()")
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210223143055.257402-4-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ian Abbott 2021-02-23 14:30:44 +00:00 committed by Greg Kroah-Hartman
parent ac0bbf55ed
commit b2e78630f7
1 changed files with 5 additions and 5 deletions
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10
drivers/staging/comedi/drivers/adv_pci1710.c
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@ -300,11 +300,11 @@ static int pci1710_ai_eoc(struct comedi_device *dev,
static int pci1710_ai_read_sample(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned int cur_chan,
unsigned int *val)
unsigned short *val)
{
const struct boardtype *board = dev->board_ptr;
struct pci1710_private *devpriv = dev->private;
unsigned int sample;
unsigned short sample;
unsigned int chan;
sample = inw(dev->iobase + PCI171X_AD_DATA_REG);
@ -345,7 +345,7 @@ static int pci1710_ai_insn_read(struct comedi_device *dev,
pci1710_ai_setup_chanlist(dev, s, &insn->chanspec, 1, 1);
for (i = 0; i < insn->n; i++) {
unsigned int val;
unsigned short val;
/* start conversion */
outw(0, dev->iobase + PCI171X_SOFTTRG_REG);
@ -395,7 +395,7 @@ static void pci1710_handle_every_sample(struct comedi_device *dev,
{
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int status;
unsigned int val;
unsigned short val;
int ret;
status = inw(dev->iobase + PCI171X_STATUS_REG);
@ -455,7 +455,7 @@ static void pci1710_handle_fifo(struct comedi_device *dev,
}
for (i = 0; i < devpriv->max_samples; i++) {
unsigned int val;
unsigned short val;
int ret;
ret = pci1710_ai_read_sample(dev, s, s->async->cur_chan, &val);