From: Ian Abbott abbotti@mev.co.uk
commit b2e78630f733a76508b53ba680528ca39c890e82 upstream.
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: a9c3a015c12f ("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 --- drivers/staging/comedi/drivers/adv_pci1710.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/comedi/drivers/adv_pci1710.c b/drivers/staging/comedi/drivers/adv_pci1710.c index c1c3b18793d50..8cdee455e8a53 100644 --- a/drivers/staging/comedi/drivers/adv_pci1710.c +++ b/drivers/staging/comedi/drivers/adv_pci1710.c @@ -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);