From: Nathan Chancellor nathan@kernel.org
commit 502408a61f4b7eb4713f44bd77f4a48e6cb1b59a upstream.
A new warning in clang points out a place in this file where a bitwise OR is being used with boolean expressions:
In file included from drivers/staging/wlan-ng/prism2usb.c:2: drivers/staging/wlan-ng/hfa384x_usb.c:3787:7: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical] ((test_and_clear_bit(THROTTLE_RX, &hw->usb_flags) && ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/staging/wlan-ng/hfa384x_usb.c:3787:7: note: cast one or both operands to int to silence this warning 1 warning generated.
The comment explains that short circuiting here is undesirable, as the calls to test_and_{clear,set}_bit() need to happen for both sides of the expression.
Clang's suggestion would work to silence the warning but the readability of the expression would suffer even more. To clean up the warning and make the block more readable, use a variable for each side of the bitwise expression.
Link: https://github.com/ClangBuiltLinux/linux/issues/1478 Signed-off-by: Nathan Chancellor nathan@kernel.org Link: https://lore.kernel.org/r/20211014215703.3705371-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/wlan-ng/hfa384x_usb.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)
--- a/drivers/staging/wlan-ng/hfa384x_usb.c +++ b/drivers/staging/wlan-ng/hfa384x_usb.c @@ -3904,18 +3904,18 @@ static void hfa384x_usb_throttlefn(unsig
spin_lock_irqsave(&hw->ctlxq.lock, flags);
- /* - * We need to check BOTH the RX and the TX throttle controls, - * so we use the bitwise OR instead of the logical OR. - */ pr_debug("flags=0x%lx\n", hw->usb_flags); - if (!hw->wlandev->hwremoved && - ((test_and_clear_bit(THROTTLE_RX, &hw->usb_flags) && - !test_and_set_bit(WORK_RX_RESUME, &hw->usb_flags)) | - (test_and_clear_bit(THROTTLE_TX, &hw->usb_flags) && - !test_and_set_bit(WORK_TX_RESUME, &hw->usb_flags)) - )) { - schedule_work(&hw->usb_work); + if (!hw->wlandev->hwremoved) { + bool rx_throttle = test_and_clear_bit(THROTTLE_RX, &hw->usb_flags) && + !test_and_set_bit(WORK_RX_RESUME, &hw->usb_flags); + bool tx_throttle = test_and_clear_bit(THROTTLE_TX, &hw->usb_flags) && + !test_and_set_bit(WORK_TX_RESUME, &hw->usb_flags); + /* + * We need to check BOTH the RX and the TX throttle controls, + * so we use the bitwise OR instead of the logical OR. + */ + if (rx_throttle | tx_throttle) + schedule_work(&hw->usb_work); }
spin_unlock_irqrestore(&hw->ctlxq.lock, flags);