Re: [PATCH] drivers/ata/libata-eh.c: fix unused variable warning

[Jeff Garzik <jeff@garzik.org>]

On 04/23/2010 03:01 AM, Tejun Heo wrote:
> Hello, Jeff.
>
> On 04/23/2010 08:43 AM, Jeff Garzik wrote:
>> On Fri, Apr 23, 2010 at 08:30:28AM +0200, Tejun Heo wrote:
>>> On 04/22/2010 03:23 AM, Fang Wenqi wrote:
>>>> Sorry that the title should be:
>>>>   "fix uninitialized variable warning"
>>>>
>>>> not
>>>> "fix unused variable warning"
>>>>
>>>> Need I re-send the patch mail ?
>>>
>>> Yes, please do so.  gcc 4.4.1 generates a spurious warning on it too.
>>>
>>> Acked-by: Tejun Heo<tj@kernel.org>
>>
>> It's not a spurious warning.  The code failed to fully initialize all
>> fields of the ata_taskfile structure, prior to copying the ata_taskfile
>> structure into qc->result_tf.
>
> Hmmmm.... right, I've always thought it was gcc not noticing the
> structure is being initialized in ata_eh_read_log_10h() but it
> actually is noticing much more, so something like the following is
> more appropriate?
>
> Subject: libata: fully initialize @tf in ata_eh_read_log_10h()
>
> ata_eh_read_log_10h() filled @tf only partially.  It didn't cause any
> correctness issues but triggered spruious uninitialized variable
> warning.  Do ata_tf_init() before filling in @tf.
>
> Signed-off-by: Tejun Heo<tj@kernel.org>

Sorry, I should have also pointed out that a fix went upstream to Linus 
in the last batch of fixes...

	Jeff