scsi: qla2xxx: Simplify conditional check

Clang generates a warning when it sees a logical not followed by a conditional operator like ==, >, or < because it thinks that the logical not should be applied to the whole statement:

drivers/scsi/qla2xxx/qla_nx.c:3702:7: warning: logical not is only applied to the left hand side of this comparison [-Wlogical-not-parentheses]

                if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
                    ^
drivers/scsi/qla2xxx/qla_nx.c:3702:7: note: add parentheses after the
'!' to evaluate the comparison first
                if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
                    ^
                     (
drivers/scsi/qla2xxx/qla_nx.c:3702:7: note: add parentheses around left
hand side expression to silence this warning
                if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
                    ^
                    (

1 warning generated.

It assumes the author might have made a mistake in their logic:

if (!a == b) -> if (!(a == b))

Sometimes that is the case; other times, it's just a super convoluted way of saying 'if (a)' when b = 0:

if (!1 == 0) -> if (0 == 0) -> if (true)

Alternatively:

if (!1 == 0) -> if (!!1) -> if (1)

Simplify this comparison so that Clang doesn't complain.

Link https://github.com/ClangBuiltLinux/linux/issues/80

Signed-off-by Nathan Chancellor <[email protected]>

---

This is commit 0bfe7d3cae58 ("scsi: qla2xxx: Simplify conditional check") upstream but commit 3695310e37b4 ("scsi: qla2xxx: Update flash read/write routine") in the 5.2/scsi-queue branch silently reverted it. I don't care if it is squashed or not, I just want the warning to stay fixed.

Thanks,
Nathan

 drivers/scsi/qla2xxx/qla_nx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/scsi/qla2xxx/qla_nx.c +2 -3

index de2bc78449e7..121e18b3b9f8 100644
@@ -3699,8 +3699,8 @@ qla82xx_chip_reset_cleanup(scsi_qla_host_t *vha)
                spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
                /* Wait for pending cmds (physical and virtual) to complete */
-               if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
-                   WAIT_HOST) == QLA_SUCCESS) {
+               if (qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
+                   WAIT_HOST)) {
                        ql_dbg(ql_dbg_init, vha, 0x00b3,
                            "Done wait for "
                            "pending commands.\n");
--

2.21.0

--
You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected].
To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20190320163315.12740-1-natechancellor%40gmail.com.
For more options, visit https://groups.google.com/d/optout.

Clang warns when it sees a logical not on the left side of a conditional statement because it thinks the logical not should be applied to the whole statement, not just the left side:

drivers/scsi/qla2xxx/qla_nx.c:3703:7: warning: logical not is only applied to the left hand side of this comparison [-Wlogical-not-parentheses]

This particular instance was already fixed by commit 0bfe7d3cae58 ("scsi:
qla2xxx: Simplify conditional check") upstream but it was reintroduced by commit 3695310e37b4 ("scsi: qla2xxx: Update flash read/write routine") in the 5.2/scsi-queue.

Fixes 3695310e37b4 ("scsi: qla2xxx: Update flash read/write routine")

Link https://github.com/ClangBuiltLinux/linux/issues/80

Signed-off-by Nathan Chancellor <[email protected]>

---

v1 -> v2:

* Reword commit message so make it clear this is just a reapplication of a commit that is already in mainline, as suggested by Nick.

* Include the authors who reintroduced this warning.

 drivers/scsi/qla2xxx/qla_nx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/scsi/qla2xxx/qla_nx.c +2 -3

index e0b4387fd6ba..359ebb634d96 100644
@@ -3700,8 +3700,8 @@ qla82xx_chip_reset_cleanup(scsi_qla_host_t *vha)
                spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
                /* Wait for pending cmds (physical and virtual) to complete */
-               if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
-                   WAIT_HOST) == QLA_SUCCESS) {
+               if (qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
+                   WAIT_HOST)) {
                        ql_dbg(ql_dbg_init, vha, 0x00b3,
                            "Done wait for "
                            "pending commands.\n");
--

2.21.0

Clang warns when it sees a logical not on the left side of a conditional statement because it thinks the logical not should be applied to the whole statement, not just the left side: