[PATCH] lightnvm: remove unused rq parameter of nvme_nvm_rqtocmd() to kill warning

[PATCH] lightnvm: remove unused rq parameter of nvme_nvm_rqtocmd() to kill warning

[Geert Uytterhoeven]

With gcc 4.1.2:

    drivers/nvme/host/lightnvm.c: In function ‘nvme_nvm_submit_io’:
    drivers/nvme/host/lightnvm.c:498: warning: ‘rq’ is used uninitialized in this function

Indeed, since commit 2e13f33a2464fc3a ("lightnvm: create cmd before
allocating request"), the request is passed to nvme_nvm_rqtocmd() before
it is allocated.

Fortunately, as of commit 91276162de9476b8 ("lightnvm: refactor end_io
functions for sync"), nvme_nvm_rqtocmd () no longer uses the passed
request, so this warning is a false positive.

Drop the unused parameter to clean up the code and kill the warning.

Fixes: 2e13f33a2464fc3a ("lightnvm: create cmd before allocating request")
Fixes: 91276162de9476b8 ("lightnvm: refactor end_io functions for sync")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
Perhaps nvme_nvm_rqtocmd() should be renamed, too?
---
 drivers/nvme/host/lightnvm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 8c4adac6fafcc56d..206bfdbc1c982b04 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -464,8 +464,8 @@ static int nvme_nvm_set_bb_tbl(struct nvm_dev *nvmdev, struct ppa_addr *ppas,
 	return ret;
 }
 
-static inline void nvme_nvm_rqtocmd(struct request *rq, struct nvm_rq *rqd,
-				struct nvme_ns *ns, struct nvme_nvm_command *c)
+static inline void nvme_nvm_rqtocmd(struct nvm_rq *rqd, struct nvme_ns *ns,
+				    struct nvme_nvm_command *c)
 {
 	c->ph_rw.opcode = rqd->opcode;
 	c->ph_rw.nsid = cpu_to_le32(ns->ns_id);
@@ -503,7 +503,7 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 	if (!cmd)
 		return -ENOMEM;
 
-	nvme_nvm_rqtocmd(rq, rqd, ns, cmd);
+	nvme_nvm_rqtocmd(rqd, ns, cmd);
 
 	rq = nvme_alloc_request(q, (struct nvme_command *)cmd, 0, NVME_QID_ANY);
 	if (IS_ERR(rq)) {
-- 
2.7.4

Re: [PATCH] lightnvm: remove unused rq parameter of nvme_nvm_rqtocmd() to kill warning

[Jens Axboe]

On 05/07/2017 08:14 AM, Geert Uytterhoeven wrote:
> With gcc 4.1.2:

Wow, that's ancient.

>     drivers/nvme/host/lightnvm.c: In function ‘nvme_nvm_submit_io’:
>     drivers/nvme/host/lightnvm.c:498: warning: ‘rq’ is used uninitialized in this function
> 
> Indeed, since commit 2e13f33a2464fc3a ("lightnvm: create cmd before
> allocating request"), the request is passed to nvme_nvm_rqtocmd() before
> it is allocated.
> 
> Fortunately, as of commit 91276162de9476b8 ("lightnvm: refactor end_io
> functions for sync"), nvme_nvm_rqtocmd () no longer uses the passed
> request, so this warning is a false positive.
> 
> Drop the unused parameter to clean up the code and kill the warning.

Thanks, applied.

-- 
Jens Axboe

Re: [PATCH] lightnvm: remove unused rq parameter of nvme_nvm_rqtocmd() to kill warning

[Geert Uytterhoeven]

Hi Jens,

On Mon, May 8, 2017 at 3:53 AM, Jens Axboe <axboe@fb.com> wrote:
> On 05/07/2017 08:14 AM, Geert Uytterhoeven wrote:
>> With gcc 4.1.2:
>
> Wow, that's ancient.

But it helps to find things like this, and improve the code ;-)

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] lightnvm: remove unused rq parameter of nvme_nvm_rqtocmd() to kill warning

[Arnd Bergmann]

On Mon, May 8, 2017 at 9:25 AM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> Hi Jens,
>
> On Mon, May 8, 2017 at 3:53 AM, Jens Axboe <axboe@fb.com> wrote:
>> On 05/07/2017 08:14 AM, Geert Uytterhoeven wrote:
>>> With gcc 4.1.2:
>>
>> Wow, that's ancient.
>
> But it helps to find things like this, and improve the code ;-)

For reference, the warning shows up in gcc-4.2 and 4.3 as well, but
not in gcc-4.4 or
higher unless you disable all optimizations (e.g. gcc-7.1 -O0 warns).

      Arnd