On Mon, Apr 24, 2023 at 08:33:18AM +0200, Greg Kroah-Hartman wrote:
> On Sun, Apr 23, 2023 at 07:20:46PM -0400, William Breathitt Gray wrote:
> > commit 4aa3b75c74603c3374877d5fd18ad9cc3a9a62ed upstream.
> >
> > The Counter (CNTR) register is 24 bits wide, but we can have an
> > effective 25-bit count value by setting bit 24 to the XOR of the Borrow
> > flag and Carry flag. The flags can be read from the FLAG register, but a
> > race condition exists: the Borrow flag and Carry flag are instantaneous
> > and could change by the time the count value is read from the CNTR
> > register.
> >
> > Since the race condition could result in an incorrect 25-bit count
> > value, remove support for 25-bit count values from this driver.
> >
> > Fixes: 28e5d3bb0325 ("iio: 104-quad-8: Add IIO support for the ACCES 104-QUAD-8")
> > Cc: <stable@xxxxxxxxxxxxxxx> # 5.10.x
> > Signed-off-by: William Breathitt Gray <william.gray@xxxxxxxxxx>
> > ---
> > drivers/counter/104-quad-8.c | 18 +++---------------
> > 1 file changed, 3 insertions(+), 15 deletions(-)
>
> This patch breaks the build:
>
> CC [M] drivers/counter/104-quad-8.o
> drivers/counter/104-quad-8.c: In function ‘quad8_read_raw’:
> drivers/counter/104-quad-8.c:117:34: error: ‘QUAD8_FLAG_BT’ undeclared (first use in this function); did you mean ‘QUAD8_FLAG_E’?
> 117 | borrow = flags & QUAD8_FLAG_BT;
> | ^~~~~~~~~~~~~
> | QUAD8_FLAG_E
> drivers/counter/104-quad-8.c:117:34: note: each undeclared identifier is reported only once for each function it appears in
> drivers/counter/104-quad-8.c:118:36: error: ‘QUAD8_FLAG_CT’ undeclared (first use in this function); did you mean ‘QUAD8_FLAG_E’?
> 118 | carry = !!(flags & QUAD8_FLAG_CT);
> | ^~~~~~~~~~~~~
> | QUAD8_FLAG_E
>
>
Ah, the 5.4 and 5.10 patches are missing the IIO changes from the 4.19
patch. I'll adjust and resubmit these two patches.
William Breathitt Gray
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