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| Started by | Arnd Bergmann <arnd@arndb.de> |
|---|---|
| First post | 2016-07-21 09:50 +0200 |
| Last post | 2016-07-21 11:50 +0200 |
| Articles | 2 — 2 participants |
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[PATCH] libata: add parentheses to avoid a gcc warning Arnd Bergmann <arnd@arndb.de> - 2016-07-21 09:50 +0200
Re: [PATCH] libata: add parentheses to avoid a gcc warning Tom Yan <tom.ty89@gmail.com> - 2016-07-21 11:50 +0200
| From | Arnd Bergmann <arnd@arndb.de> |
|---|---|
| Date | 2016-07-21 09:50 +0200 |
| Subject | [PATCH] libata: add parentheses to avoid a gcc warning |
| Message-ID | <rXgU1-4ur-15@gated-at.bofh.it> |
gcc-6.1 warns about possibly ambiguous code that was newly added
to libata:
drivers/ata/libata-scsi.c: In function 'ata_mselect_caching':
drivers/ata/libata-scsi.c:3637:28: error: suggest parentheses around comparison in operand of '&' [-Werror=parentheses]
drivers/ata/libata-scsi.c: In function 'ata_mselect_control':
drivers/ata/libata-scsi.c:3702:28: error: suggest parentheses around comparison in operand of '&' [-Werror=parentheses]
The code is fine, and it's not really ambigous to human readers,
but let's shut up the warning anyway by adding the parentheses
that gcc suggests.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 9b7844a8c34a ("libata-scsi: fix read-only bits checking in ata_mselect_*()")
---
drivers/ata/libata-scsi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index fa9d16fe295c..8ad4b237f342 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3634,7 +3634,7 @@ static int ata_mselect_caching(struct ata_queued_cmd *qc,
/* Check the first byte */
if (i == 0) {
/* except the WCE bit */
- if (mpage[i + 2] & 0xfb != buf[i] & 0xfb) {
+ if ((mpage[i + 2] & 0xfb) != (buf[i] & 0xfb)) {
*fp = i;
return -EINVAL;
} else {
@@ -3699,7 +3699,7 @@ static int ata_mselect_control(struct ata_queued_cmd *qc,
/* Check the first byte */
if (i == 0) {
/* except the D_SENSE bit */
- if (mpage[i + 2] & 0xfb != buf[i] & 0xfb) {
+ if ((mpage[i + 2] & 0xfb) != (buf[i] & 0xfb)) {
*fp = i;
return -EINVAL;
} else {
--
2.9.0
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| From | Tom Yan <tom.ty89@gmail.com> |
|---|---|
| Date | 2016-07-21 11:50 +0200 |
| Message-ID | <rXiMa-5GH-29@gated-at.bofh.it> |
| In reply to | #1447680 |
The commit has been reverted. The parentheses are actually necessary
since `!=` is of higher precedence than `&`. My bad.
On 21 July 2016 at 15:40, Arnd Bergmann <arnd@arndb.de> wrote:
> gcc-6.1 warns about possibly ambiguous code that was newly added
> to libata:
>
> drivers/ata/libata-scsi.c: In function 'ata_mselect_caching':
> drivers/ata/libata-scsi.c:3637:28: error: suggest parentheses around comparison in operand of '&' [-Werror=parentheses]
> drivers/ata/libata-scsi.c: In function 'ata_mselect_control':
> drivers/ata/libata-scsi.c:3702:28: error: suggest parentheses around comparison in operand of '&' [-Werror=parentheses]
>
> The code is fine, and it's not really ambigous to human readers,
> but let's shut up the warning anyway by adding the parentheses
> that gcc suggests.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 9b7844a8c34a ("libata-scsi: fix read-only bits checking in ata_mselect_*()")
> ---
> drivers/ata/libata-scsi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index fa9d16fe295c..8ad4b237f342 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -3634,7 +3634,7 @@ static int ata_mselect_caching(struct ata_queued_cmd *qc,
> /* Check the first byte */
> if (i == 0) {
> /* except the WCE bit */
> - if (mpage[i + 2] & 0xfb != buf[i] & 0xfb) {
> + if ((mpage[i + 2] & 0xfb) != (buf[i] & 0xfb)) {
> *fp = i;
> return -EINVAL;
> } else {
> @@ -3699,7 +3699,7 @@ static int ata_mselect_control(struct ata_queued_cmd *qc,
> /* Check the first byte */
> if (i == 0) {
> /* except the D_SENSE bit */
> - if (mpage[i + 2] & 0xfb != buf[i] & 0xfb) {
> + if ((mpage[i + 2] & 0xfb) != (buf[i] & 0xfb)) {
> *fp = i;
> return -EINVAL;
> } else {
> --
> 2.9.0
>
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