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staging: wlan-ng: Avoid bitwise vs logical OR warning in hfa384x_usb_throttlefn() 

commit 502408a61f 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>
This commit is contained in:
Nathan Chancellor 2021-10-14 14:57:03 -07:00 committed by Greg Kroah-Hartman
parent f01ddd4824
commit 4b98de4c58
1 changed files with 11 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/staging/wlan-ng/hfa384x_usb.c
View File

@ -3848,18 +3848,18 @@ static void hfa384x_usb_throttlefn(unsigned long data)
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);