Re: [PATCH] staging: unisys: uislib: uisqueue.c: fixed sparse warning of context imbalance

From: Sudip Mukherjee
Date: Tue Sep 02 2014 - 11:14:55 EST


On Tue, Sep 02, 2014 at 05:05:32PM +0300, Dan Carpenter wrote:
> On Tue, Sep 02, 2014 at 04:39:47PM +0530, Sudip Mukherjee wrote:
> > fixed sparse warning : context imbalance in 'do_locked_client_insert'
> > different lock contexts for basic block
> >
> > spin_unlock_irqrestore is called at a later stage before returning
> > from the function if locked is 1.
> >
> > Signed-off-by: Sudip Mukherjee <sudip@xxxxxxxxxxxxxxx>
>
> This doesn't match the email address you are using.
>

for all my patch the Signed-off email address is different from the From email address.
I am not sure if I should do that, but since no one pointed it out so I guessed it is ok.

> Really, your patch isn't bad but I would prefer if you re-wrote this
> entire function because currently it is garbage.
>
> static u8
> do_locked_client_insert(struct uisqueue_info *queueinfo,
> unsigned int whichqueue,
> void *pSignal,
> spinlock_t *lock,
> unsigned char issueInterruptIfEmpty,
> u64 interruptHandle, u8 *channelId)
> {
> unsigned long flags;
> unsigned char queueWasEmpty;
>
> spin_lock_irqsave(lock, flags);
>
> if (!ULTRA_CHANNEL_CLIENT_ACQUIRE_OS(queueinfo->chan, channelId, NULL))
> goto unlock;
>
> queueWasEmpty = visor_signalqueue_empty(queueinfo->chan, whichqueue);
> if (!visor_signal_insert(queueinfo->chan, whichqueue, pSignal))
> goto release;
> ULTRA_CHANNEL_CLIENT_RELEASE_OS(queueinfo->chan, channelId, NULL);
> spin_unlock_irqrestore(lock, flags);
>
> queueinfo->packets_sent++;
>
> return 1;
>
> release:
> ULTRA_CHANNEL_CLIENT_RELEASE_OS(queueinfo->chan, channelId, NULL);
> unlock:
> spin_unlock_irqrestore(lock, flags);
>
> return 0;
> }
>
> The queueWasEmpty variable is kind of silly. It should just be an int
> or maybe a bool if you are being pedantic but instead we very
> specifically set it to be an unsigned variable of the incorrect type.
> Also we don't use queueWasEmpty at all. I think we could delete it...
>
> The problem with the original code was that the error paths and the
> success paths were mixed together like spaghetti. If you separate them
> out and unwind in the proper order with normal label names then the
> code is easy to understand.
>
> regards,
> dan carpenter
>
I will send a modified patch with the required changes.

thanks
sudip

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