Re: [PATCH 4/4] speakup: Serialize synth clearing against locked readers

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Hello,

Indeed, the check for the synth pointer should be guarded, so it doesn't
disappear suddenly.

Your patch makes sense, but while at it:

> diff --git a/drivers/accessibility/speakup/devsynth.c b/drivers/accessibility/speakup/devsynth.c
> index e3d909bd04804..19799a362948d 100644
> --- a/drivers/accessibility/speakup/devsynth.c
> +++ b/drivers/accessibility/speakup/devsynth.c
> @@ -29,6 +29,10 @@ static ssize_t speakup_file_write(struct file *fp, const char __user *buffer,
>  		count -= bytes;
>  		ptr += bytes;
>  		spin_lock_irqsave(&speakup_info.spinlock, flags);
> +		if (!synth) {
> +			spin_unlock_irqrestore(&speakup_info.spinlock, flags);
> +			return -ENODEV;
> +		}
>  		synth_write(buf, bytes);
>  		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
>  	}

You can as well remove the check above for simplicity, since it becomes duplicate.

That is the same in mostly all other places of the patch.

Thanks,
Samuel