[Skiboot] [PATCH v2 5/7] npu2-opencapi: ODL should be in reset when enabled

[Andrew Donnellan]

On 13/3/19 7:35 am, Frederic Barrat wrote:
> We haven't hit any problem so far, but from the ODL designer, the ODL
> should be in reset when it is enabled.
> 
> The ODL remains in reset until we start a fundamental reset to
> initiate link training. We still assert and deassert the ODL reset
> signal as part of the normal procedure just before training the
> link. Asserting is therefore useless at boot, since the ODL is already
> in reset, but we keep it as it's only a scom write and it's needed
> when we reset/retrain from the OS.
> 
> Signed-off-by: Frederic Barrat <fbarrat at linux.ibm.com>

Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>

> ---
> 
> v2: update commit message
> 
>   hw/npu2-opencapi.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/hw/npu2-opencapi.c b/hw/npu2-opencapi.c
> index 87e64492..223888e6 100644
> --- a/hw/npu2-opencapi.c
> +++ b/hw/npu2-opencapi.c
> @@ -308,6 +308,12 @@ static void enable_odl_phy_mux(uint32_t gcid, int index)
>   		assert(false);
>   	}
>   
> +	/*
> +	 * ODL must be in reset when enabling.
> +	 * It stays in reset until the link is trained
> +	 */
> +	assert_odl_reset(gcid, index);
> +
>   	/* PowerBus OLL PHY Training Config Register */
>   	xscom_read(gcid, phy_config_scom, &reg);
>   
> 

-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan at au1.ibm.com  IBM Australia Limited