Re: [PATCH 07/17] pnv_phb4.c: check if root port exists in rc_config functions

[Cédric Le Goater]

On 12/28/21 20:37, Daniel Henrique Barboza wrote:
> pnv_phb4_rc_config_read() and pnv_phb4_rc_config_write() are asserting
> the existence of the root port. The root port is now optional, and there
> will be cases where a pnv-phb4 device won't have a root port attached.

May be we should enforce a stronger link between the two objects to avoid
creating an empty PHB device.

> Instead of asserting, check if the root port exists before read/writing
> into it> 
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>   hw/pci-host/pnv_phb4.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
> index daa468b812..6bd907f91a 100644
> --- a/hw/pci-host/pnv_phb4.c
> +++ b/hw/pci-host/pnv_phb4.c
> @@ -152,7 +152,9 @@ static void pnv_phb4_rc_config_write(PnvPHB4 *phb, unsigned 
> off,
>       }
>   
>       pdev = pci_find_device(pci->bus, 0, 0);
> -    assert(pdev);
> +    if (!pdev) {

We should log an error at least.

> +        return;
> +    }
>   
>       pci_host_config_write_common(pdev, off, PHB_RC_CONFIG_SIZE,
>                                    bswap32(val), 4);
> @@ -171,7 +173,9 @@ static uint64_t pnv_phb4_rc_config_read(PnvPHB4 *phb, 
> unsigned off,
>       }
>   
>       pdev = pci_find_device(pci->bus, 0, 0);
> -    assert(pdev);
> +    if (!pdev) {
> +        return 0x0;

        return ~0ull;

> +    }
>   
>       val = pci_host_config_read_common(pdev, off, PHB_RC_CONFIG_SIZE, 4);
>       return bswap32(val);