Re: [PATCH 1/6] ath6kl: fix sparse warning on init.c

Kalle Valo
2011-12-20T19:40:27Z

On 12/20/2011 08:46 PM, Luis R. Rodriguez wrote:
> From: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
>
> This fixes this sparse warning:
>
> CC [M] drivers/net/wireless/ath/ath6kl/init.o
> drivers/net/wireless/ath/ath6kl/init.c: In function ‘ath6kl_init_hw_params’:
> drivers/net/wireless/ath/ath6kl/init.c:1377:26: warning: ‘hw’ may be used uninitialized in this function

That's a compiler warning.

> static int ath6kl_init_hw_params(struct ath6kl *ar)
> {
> - const struct ath6kl_hw *hw;
> + const struct ath6kl_hw *hw = NULL;
> int i;
>
> for (i = 0; i < ARRAY_SIZE(hw_list); i++) {
> @@ -1390,6 +1390,9 @@ static int ath6kl_init_hw_params(struct ath6kl *ar)
> return -EINVAL;
> }
>
> + if (!hw)
> + return -EINVAL;

I can't see how hw can be uninitialised here (looking at the version in
ath6kl.git). I copy the full code here:

static int ath6kl_init_hw_params(struct ath6kl *ar)
{
const struct ath6kl_hw *hw;
int i;

for (i = 0; i < ARRAY_SIZE(hw_list); i++) {
hw = &hw_list[i];

if (hw->id == ar->version.target_ver)
break;
}

if (i == ARRAY_SIZE(hw_list)) {
ath6kl_err("Unsupported hardware version: 0x%x\n",
ar->version.target_ver);
return -EINVAL;
}

ar->hw = *hw;

I always check for both compiler and sparse warnings and I have never
seen this. What version of compiler do you have?

I have:

gcc-4.5.real (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2

Kalle