[Skiboot] [PATCH] capi: Disable CAPP virtual machines

[Andrew Donnellan]

On 16/01/18 17:06, Vaibhav Jain wrote:
> When exercising more than one CAPI accelerators simultaneously in
> cache coherency mode, the verification team is seeing a deadlock. To
> fix this a workaround of disabling CAPP virtual machines is
> suggested. So this patch updates CAPP APC Master Powerbus control
> register during CAPP init to also set Bit(12) that disables CAPP
> virtual machines.
> 
> Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>

What's a "virtual machine" mean in this context? The SCOM documentation 
says that bit disables PSL command queues - I think I can take a guess 
at what a "virtual machine" is given that information, but some more 
context would be helpful.

> ---
>   hw/phb4.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/hw/phb4.c b/hw/phb4.c
> index ff912e1f..8e660b66 100644
> --- a/hw/phb4.c
> +++ b/hw/phb4.c
> @@ -3581,6 +3581,7 @@ static void phb4_init_capp_regs(struct phb4 *p, uint32_t capp_eng)
>   	xscom_read(p->chip_id, APC_MASTER_PB_CTRL + offset, &reg);
>   	reg |= PPC_BIT(0); /* enable cResp exam */
>   	reg |= PPC_BIT(3); /* disable vg not sys */
> +	reg |= PPC_BIT(12);/* HW417025: disable capp virtual machines */
>   	if (p->rev == PHB4_REV_NIMBUS_DD10) {
>   		reg |= PPC_BIT(1);
>   	} else {
> 

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