[PATCH 0/3] Fix clang -Wunused-but-set-variable warnings

STALE1864d

Revision v1 of 2 in this series.

11 messages, 4 authors, 2021-07-29 · open the first message on its own page

[PATCH 0/3] Fix clang -Wunused-but-set-variable warnings

From: Bill Wendling <morbo@google.com>
Date: 2021-07-14 09:18:00

These patches clean up warnings from clang's '-Wunused-but-set-variable' flag.

Bill Wendling (3):
  base: remove unused variable 'no_warn'
  bnx2x: remove unused variable 'cur_data_offset'
  scsi: qla2xxx: remove unused variable 'status'

 drivers/base/module.c                             | 6 ++----
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 6 ------
 drivers/scsi/qla2xxx/qla_nx.c                     | 2 --
 3 files changed, 2 insertions(+), 12 deletions(-)

-- 
2.32.0.93.g670b81a890-goog

[PATCH 1/3] base: remove unused variable 'no_warn'

From: Bill Wendling <morbo@google.com>
Date: 2021-07-14 09:18:05

Fix the following build warning:

  drivers/base/module.c:36:6: error: variable 'no_warn' set but not used [-Werror,-Wunused-but-set-variable]
        int no_warn;

Signed-off-by: Bill Wendling <morbo@google.com>
---
 drivers/base/module.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/base/module.c b/drivers/base/module.c
index 46ad4d636731..81d84a066a38 100644
--- a/drivers/base/module.c
+++ b/drivers/base/module.c

@@ -33,7 +33,6 @@ static void module_create_drivers_dir(struct module_kobject *mk)
 void module_add_driver(struct module *mod, struct device_driver *drv)
 {
 	char *driver_name;
-	int no_warn;
 	struct module_kobject *mk = NULL;
 
 	if (!drv)

@@ -59,12 +58,11 @@ void module_add_driver(struct module *mod, struct device_driver *drv)
 		return;
 
 	/* Don't check return codes; these calls are idempotent */
-	no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
+	sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
 	driver_name = make_driver_name(drv);
 	if (driver_name) {
 		module_create_drivers_dir(mk);
-		no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj,
-					    driver_name);
+		sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name);
 		kfree(driver_name);
 	}
 }

-- 
2.32.0.93.g670b81a890-goog

[PATCH 2/3] bnx2x: remove unused variable 'cur_data_offset'

From: Bill Wendling <morbo@google.com>
Date: 2021-07-14 09:18:12

Fix the clang build warning:

  drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:1862:13: error: variable 'cur_data_offset' set but not used [-Werror,-Wunused-but-set-variable]
        dma_addr_t cur_data_offset;

Signed-off-by: Bill Wendling <morbo@google.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
index 27943b0446c2..f255fd0b16db 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c

@@ -1858,7 +1858,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
 {
 	int i;
 	int first_queue_query_index, num_queues_req;
-	dma_addr_t cur_data_offset;
 	struct stats_query_entry *cur_query_entry;
 	u8 stats_count = 0;
 	bool is_fcoe = false;

@@ -1879,10 +1878,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
 	       BNX2X_NUM_ETH_QUEUES(bp), is_fcoe, first_queue_query_index,
 	       first_queue_query_index + num_queues_req);
 
-	cur_data_offset = bp->fw_stats_data_mapping +
-		offsetof(struct bnx2x_fw_stats_data, queue_stats) +
-		num_queues_req * sizeof(struct per_queue_stats);
-
 	cur_query_entry = &bp->fw_stats_req->
 		query[first_queue_query_index + num_queues_req];

@@ -1933,7 +1928,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
 			       cur_query_entry->funcID,
 			       j, cur_query_entry->index);
 			cur_query_entry++;
-			cur_data_offset += sizeof(struct per_queue_stats);
 			stats_count++;
 
 			/* all stats are coalesced to the leading queue */

-- 
2.32.0.93.g670b81a890-goog

[PATCH 3/3] scsi: qla2xxx: remove unused variable 'status'

From: Bill Wendling <morbo@google.com>
Date: 2021-07-14 09:18:14

Fix the clang build warning:

  drivers/scsi/qla2xxx/qla_nx.c:2209:6: error: variable 'status' set but not used [-Werror,-Wunused-but-set-variable]
        int status = 0;

Signed-off-by: Bill Wendling <morbo@google.com>
---
 drivers/scsi/qla2xxx/qla_nx.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_nx.c b/drivers/scsi/qla2xxx/qla_nx.c
index 615e44af1ca6..11aad97dfca8 100644
--- a/drivers/scsi/qla2xxx/qla_nx.c
+++ b/drivers/scsi/qla2xxx/qla_nx.c

@@ -2166,7 +2166,6 @@ qla82xx_poll(int irq, void *dev_id)
 	struct qla_hw_data *ha;
 	struct rsp_que *rsp;
 	struct device_reg_82xx __iomem *reg;
-	int status = 0;
 	uint32_t stat;
 	uint32_t host_int = 0;
 	uint16_t mb[8];

@@ -2195,7 +2194,6 @@ qla82xx_poll(int irq, void *dev_id)
 		case 0x10:
 		case 0x11:
 			qla82xx_mbx_completion(vha, MSW(stat));
-			status |= MBX_INTERRUPT;
 			break;
 		case 0x12:
 			mb[0] = MSW(stat);

-- 
2.32.0.93.g670b81a890-goog

Re: [PATCH 1/3] base: remove unused variable 'no_warn'

From: kernel test robot <hidden>
Date: 2021-07-14 12:15:43

Hi Bill,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on scsi/for-next]
[also build test WARNING on linux/master driver-core/driver-core-testing mkp-scsi/for-next ipvs/master linus/master v5.14-rc1 next-20210714]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Bill-Wendling/Fix-clang-Wunused-but-set-variable-warnings/20210714-172029
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
config: powerpc-redwood_defconfig (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/f6c4b007fc8c907719d883faae424f2cf3bb100c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Bill-Wendling/Fix-clang-Wunused-but-set-variable-warnings/20210714-172029
        git checkout f6c4b007fc8c907719d883faae424f2cf3bb100c
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>):

   drivers/base/module.c: In function 'module_add_driver':

quoted

drivers/base/module.c:61:2: warning: ignoring return value of 'sysfs_create_link', declared with attribute warn_unused_result [-Wunused-result]

      61 |  sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
         |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/base/module.c:65:3: warning: ignoring return value of 'sysfs_create_link', declared with attribute warn_unused_result [-Wunused-result]
      65 |   sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name);
         |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/sysfs_create_link +61 drivers/base/module.c

    32	
    33	void module_add_driver(struct module *mod, struct device_driver *drv)
    34	{
    35		char *driver_name;
    36		struct module_kobject *mk = NULL;
    37	
    38		if (!drv)
    39			return;
    40	
    41		if (mod)
    42			mk = &mod->mkobj;
    43		else if (drv->mod_name) {
    44			struct kobject *mkobj;
    45	
    46			/* Lookup built-in module entry in /sys/modules */
    47			mkobj = kset_find_obj(module_kset, drv->mod_name);
    48			if (mkobj) {
    49				mk = container_of(mkobj, struct module_kobject, kobj);
    50				/* remember our module structure */
    51				drv->p->mkobj = mk;
    52				/* kset_find_obj took a reference */
    53				kobject_put(mkobj);
    54			}
    55		}
    56	
    57		if (!mk)
    58			return;
    59	
    60		/* Don't check return codes; these calls are idempotent */
  > 61		sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
    62		driver_name = make_driver_name(drv);
    63		if (driver_name) {
    64			module_create_drivers_dir(mk);
    65			sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name);
    66			kfree(driver_name);
    67		}
    68	}
    69	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[PATCH v2 0/3] Fix clang -Wunused-but-set-variable warnings

From: Bill Wendling <morbo@google.com>
Date: 2021-07-26 20:19:33

These patches clean up warnings from clang's '-Wunused-but-set-variable' flag.

Changes for v2:
- Mark "no_warn" as "__maybe_unused" to avoid separate warning.

Bill Wendling (3):
  base: mark 'no_warn' as unused
  bnx2x: remove unused variable 'cur_data_offset'
  scsi: qla2xxx: remove unused variable 'status'

 drivers/base/module.c                             | 2 +-
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 6 ------
 drivers/scsi/qla2xxx/qla_nx.c                     | 2 --
 3 files changed, 1 insertion(+), 9 deletions(-)

-- 
2.32.0.432.gabb21c7263-goog

[PATCH v2 1/3] base: mark 'no_warn' as unused

From: Bill Wendling <morbo@google.com>
Date: 2021-07-26 20:19:36

Fix the following build warning:

  drivers/base/module.c:36:6: error: variable 'no_warn' set but not used [-Werror,-Wunused-but-set-variable]
        int no_warn;

This variable is used to remove another warning, but causes a warning
itself. Mark it as 'unused' to avoid that.

Signed-off-by: Bill Wendling <morbo@google.com>
---
 drivers/base/module.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/module.c b/drivers/base/module.c
index 46ad4d636731..10494336d601 100644
--- a/drivers/base/module.c
+++ b/drivers/base/module.c

@@ -33,7 +33,7 @@ static void module_create_drivers_dir(struct module_kobject *mk)
 void module_add_driver(struct module *mod, struct device_driver *drv)
 {
 	char *driver_name;
-	int no_warn;
+	int __maybe_unused no_warn;
 	struct module_kobject *mk = NULL;
 
 	if (!drv)

-- 
2.32.0.432.gabb21c7263-goog

[PATCH v2 2/3] bnx2x: remove unused variable 'cur_data_offset'

From: Bill Wendling <morbo@google.com>
Date: 2021-07-26 20:19:44

Fix the clang build warning:

  drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:1862:13: error: variable 'cur_data_offset' set but not used [-Werror,-Wunused-but-set-variable]
        dma_addr_t cur_data_offset;

Signed-off-by: Bill Wendling <morbo@google.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
index 27943b0446c2..f255fd0b16db 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c

@@ -1858,7 +1858,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
 {
 	int i;
 	int first_queue_query_index, num_queues_req;
-	dma_addr_t cur_data_offset;
 	struct stats_query_entry *cur_query_entry;
 	u8 stats_count = 0;
 	bool is_fcoe = false;

@@ -1879,10 +1878,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
 	       BNX2X_NUM_ETH_QUEUES(bp), is_fcoe, first_queue_query_index,
 	       first_queue_query_index + num_queues_req);
 
-	cur_data_offset = bp->fw_stats_data_mapping +
-		offsetof(struct bnx2x_fw_stats_data, queue_stats) +
-		num_queues_req * sizeof(struct per_queue_stats);
-
 	cur_query_entry = &bp->fw_stats_req->
 		query[first_queue_query_index + num_queues_req];

@@ -1933,7 +1928,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
 			       cur_query_entry->funcID,
 			       j, cur_query_entry->index);
 			cur_query_entry++;
-			cur_data_offset += sizeof(struct per_queue_stats);
 			stats_count++;
 
 			/* all stats are coalesced to the leading queue */

-- 
2.32.0.432.gabb21c7263-goog

[PATCH v2 3/3] scsi: qla2xxx: remove unused variable 'status'

From: Bill Wendling <morbo@google.com>
Date: 2021-07-26 20:21:20

Fix the clang build warning:

  drivers/scsi/qla2xxx/qla_nx.c:2209:6: error: variable 'status' set but not used [-Werror,-Wunused-but-set-variable]
        int status = 0;

Signed-off-by: Bill Wendling <morbo@google.com>
---
 drivers/scsi/qla2xxx/qla_nx.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_nx.c b/drivers/scsi/qla2xxx/qla_nx.c
index 615e44af1ca6..11aad97dfca8 100644
--- a/drivers/scsi/qla2xxx/qla_nx.c
+++ b/drivers/scsi/qla2xxx/qla_nx.c

@@ -2166,7 +2166,6 @@ qla82xx_poll(int irq, void *dev_id)
 	struct qla_hw_data *ha;
 	struct rsp_que *rsp;
 	struct device_reg_82xx __iomem *reg;
-	int status = 0;
 	uint32_t stat;
 	uint32_t host_int = 0;
 	uint16_t mb[8];

@@ -2195,7 +2194,6 @@ qla82xx_poll(int irq, void *dev_id)
 		case 0x10:
 		case 0x11:
 			qla82xx_mbx_completion(vha, MSW(stat));
-			status |= MBX_INTERRUPT;
 			break;
 		case 0x12:
 			mb[0] = MSW(stat);

-- 
2.32.0.432.gabb21c7263-goog

Re: [PATCH v2 2/3] bnx2x: remove unused variable 'cur_data_offset'

From: Nathan Chancellor <nathan@kernel.org>
Date: 2021-07-26 20:36:54

On 7/26/2021 1:19 PM, 'Bill Wendling' via Clang Built Linux wrote:

Fix the clang build warning:

   drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:1862:13: error: variable 'cur_data_offset' set but not used [-Werror,-Wunused-but-set-variable]
         dma_addr_t cur_data_offset;

Signed-off-by: Bill Wendling <morbo@google.com>

It has been unused since the function's introduction in commit 
67c431a5f2f3 ("bnx2x: Support statistics collection for VFs by the PF"), 
perhaps a leftover remnant from a previous version?

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

quoted hunk

---
  drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 6 ------
  1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
index 27943b0446c2..f255fd0b16db 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c

@@ -1858,7 +1858,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
  {
  	int i;
  	int first_queue_query_index, num_queues_req;
-	dma_addr_t cur_data_offset;
  	struct stats_query_entry *cur_query_entry;
  	u8 stats_count = 0;
  	bool is_fcoe = false;

@@ -1879,10 +1878,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
  	       BNX2X_NUM_ETH_QUEUES(bp), is_fcoe, first_queue_query_index,
  	       first_queue_query_index + num_queues_req);
  
-	cur_data_offset = bp->fw_stats_data_mapping +
-		offsetof(struct bnx2x_fw_stats_data, queue_stats) +
-		num_queues_req * sizeof(struct per_queue_stats);
-
  	cur_query_entry = &bp->fw_stats_req->
  		query[first_queue_query_index + num_queues_req];

@@ -1933,7 +1928,6 @@ void bnx2x_iov_adjust_stats_req(struct bnx2x *bp)
  			       cur_query_entry->funcID,
  			       j, cur_query_entry->index);
  			cur_query_entry++;
-			cur_data_offset += sizeof(struct per_queue_stats);
  			stats_count++;
  
  			/* all stats are coalesced to the leading queue */

Re: [PATCH v2 0/3] Fix clang -Wunused-but-set-variable warnings

From: Martin K. Petersen <hidden>
Date: 2021-07-29 03:39:28

On Mon, 26 Jul 2021 13:19:21 -0700, Bill Wendling wrote:

These patches clean up warnings from clang's '-Wunused-but-set-variable' flag.

Changes for v2:
- Mark "no_warn" as "__maybe_unused" to avoid separate warning.

Bill Wendling (3):
  base: mark 'no_warn' as unused
  bnx2x: remove unused variable 'cur_data_offset'
  scsi: qla2xxx: remove unused variable 'status'

[...]

Applied to 5.15/scsi-queue, thanks!

[3/3] scsi: qla2xxx: remove unused variable 'status'
      https://git.kernel.org/mkp/scsi/c/cb51bcd5c34b

-- 
Martin K. Petersen	Oracle Linux Engineering

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