[Skiboot] [PATCH 4/4] psi: Properly mask errors in SEMR

[Ananth N Mavinakayanahalli]

On Tue, Jun 05, 2018 at 04:43:37PM +0930, Joel Stanley wrote:
> It looks like this code intended to read PSIHB SEMR, mask out some of
> the values, and write it back. Instead it writes the mask to the
> register.
> 
> Found using scan-build.
> 
> Fixes: 39addc6a0f1f ("PSI: Reorganize PSI link down handling code")
> Signed-off-by: Joel Stanley <joel at jms.id.au>
> ---
>  hw/psi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/psi.c b/hw/psi.c
> index f7d8cd9a459d..f5168ba96765 100644
> --- a/hw/psi.c
> +++ b/hw/psi.c
> @@ -74,7 +74,7 @@ void psi_disable_link(struct psi *psi)
> 
>  		/* Mask errors in SEMR */
>  		reg = in_be64(psi->regs + PSIHB_SEMR);
> -		reg = ((0xfffull << 36) | (0xfffull << 20));
> +		reg &= ((0xfffull << 36) | (0xfffull << 20));
>  		out_be64(psi->regs + PSIHB_SEMR, reg);
>  		printf("PSI: SEMR set to %llx\n", reg);

This is actually the PSIHBCR error mask register, bits of which when set
will prevent the corresponding PSIHBCR bits to be set. The existing
logic is fine for this case...

Ananth