[PATCH 0/3 V3] usb: usbtmc: Fix erroneous ioctl returns

[Dave Penkler <dpenkler@gmail.com>]

Recent tests with timeouts > INT_MAX produced random error returns
with usbtmc_get_stb. This was caused by assigning the return value
of wait_event_interruptible_timeout to an int which overflowed to
negative values. Also return value on success was the remaining
number of jiffies instead of 0.

These patches fix all the cases where the return of
wait_event_interruptible_timeout was assigned to an int and
the case of the remaining jiffies return in usbtmc_get_stb.

Patch 1: Fixes usbtmc_get_stb 
Patch 2: Fixes usbtmc488_ioctl_wait_srq
Patch 3: Fixes usbtmc_generic_read

Dave Penkler (3):
  usb: usbtmc: Fix erroneous get_stb ioctl error returns
  usb: usbtmc: Fix erroneous wait_srq ioctl return
  usb: usbtmc: Fix erroneous generic_read ioctl return

 drivers/usb/class/usbtmc.c | 53 ++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 22 deletions(-)

--
Changes V1 => V2 Add cc to stable line
        V2 => V3 Add susbsystem to cover letter
2.49.0