[linux-yocto] [PATCH 12/94] arch/powerpc: Release the lock when ncr_read() completes.

[Jacques, John M (John)]

The RTE is an external module that allows the rest of the Axxia hardware (the network processor part) to be used.  One of the ways to access registers in the network processor is via the config ring (ncr).  Since the config ring gets used by Linux, the module, and possibly external devices via PCI, there is a locking mechanism in the hardware.  Without the patch below, Linux holds the lock indefinitely.

-----Original Message-----
From: Bruce Ashfield [mailto:bruce.ashfield at windriver.com] 
Sent: Saturday, November 09, 2013 8:19 AM
To: Paul Butler; linux-yocto at yoctoproject.org
Cc: Jacques, John M (John)
Subject: Re: [PATCH 12/94] arch/powerpc: Release the lock when ncr_read() completes.

On 11/7/2013, 8:12 PM, Paul Butler wrote:
> From: John Jacques <john.jacques at lsi.com>
>
> Without this the RTE won't load.

Anymore detail ? Like the error message the user sees ?

Bruce

>
> Signed-off-by: John Jacques <john.jacques at lsi.com>
> ---
>   arch/powerpc/sysdev/lsi_acp_ncr.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/arch/powerpc/sysdev/lsi_acp_ncr.c b/arch/powerpc/sysdev/lsi_acp_ncr.c
> index 9802110..736ca5d 100644
> --- a/arch/powerpc/sysdev/lsi_acp_ncr.c
> +++ b/arch/powerpc/sysdev/lsi_acp_ncr.c
> @@ -211,6 +211,8 @@ ncr_read(unsigned long region, unsigned long address, int number, void *buffer)
>   		memcpy((void *) buffer, &temp, number);
>   	}
>
> +	ncr_unlock(LOCK_DOMAIN);
> +
>   	return 0;
>   }
>   EXPORT_SYMBOL(ncr_read);
>