On 09/11/18 23:44, Ben Hutchings wrote:
On Tue, 2018-07-10 at 18:02 +0100, Ian Abbott wrote:
From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 1376b0a2160319125c3a2822e8c09bd283cd8141 ]
There is a '>' vs '<' typo so this loop is a no-op.
Thanks, but this driver seems to have lots of other bugs in 3.16, like it only ever accesses data[0] in this loop. I don't think there's much point in applying just this one. But if you think it's worth fixing then I can apply all the necessary fixes.
Ben.
It restores some basic functionality for daqp_ao_insn_write() that was broken. The most common case to be handled is insn->n == 1, as that is what the comedi_data_write() function in the user-space Comedilib library sets.
However, it may be worth applying e024181b02ed ("staging: comedi: quatech_daqp_cs: fix bug in daqp_ao_insn_write()") and (with a small amount of backporting) e031642eccc0 ("staging: comedi: quatech_daqp_cs: use comedi_timeout() in ao (*insn_write)") before this one. I'll append a patch series as replies to this email.
Fixes: d35dcc89fc93 ("staging: comedi: quatech_daqp_cs: fix daqp_ao_insn_write()") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: Ian Abbott abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
drivers/staging/comedi/drivers/quatech_daqp_cs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c b/drivers/staging/comedi/drivers/quatech_daqp_cs.c index b3bbec0a0d23..f89a863ea04c 100644 --- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c +++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c @@ -649,7 +649,7 @@ static int daqp_ao_insn_write(struct comedi_device *dev, /* Make sure D/A update mode is direct update */ outb(0, dev->iobase + DAQP_AUX);
- for (i = 0; i > insn->n; i++) {
- for (i = 0; i < insn->n; i++) { val = data[0]; val &= 0x0fff; val ^= 0x0800; /* Flip the sign */