Thanks for the reply!
Den tors 4 jan. 2024 kl 09:41 skrev Shinichiro Kawasaki
<shinichiro.kawasaki@xxxxxxx>:
> Could you confirm that p2sb_bar() is not called during boot process on your
> system? Applying the one liner printk patch below, let's confirm that the
> string "p2sb_bar" does not appear in the dmesg log.
>
> diff --git a/drivers/platform/x86/p2sb.c b/drivers/platform/x86/p2sb.c
> index 99a0e456f075..e034a58d7531 100644
> --- a/drivers/platform/x86/p2sb.c
> +++ b/drivers/platform/x86/p2sb.c
> @@ -195,6 +195,7 @@ int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
> struct p2sb_res_cache *cache;
> int ret;
>
> + printk("%s\n", __func__);
> bus = p2sb_get_bus(bus);
> if (!bus)
> return -ENODEV;
p2sb_bar does indeed not appear in the kernel log with this patch
snippet applied.
> My mere idea was to just blacklist Intel CPUs with family != 6. If my guesses
> are all correct, following patch will avoid the failure on the reported system,
> since the system has CPU with family == 0xf. This will cover certain amount of
> old CPUs which should not access DEVFN 31:1 as P2SB. But family 6 started around
> 2006, then it is not the complete blacklist, probably. I will think about the
> better way.
>
> diff --git a/drivers/platform/x86/p2sb.c b/drivers/platform/x86/p2sb.c
> index 99a0e456f075..c9bcef8e2c4c 100644
> --- a/drivers/platform/x86/p2sb.c
> +++ b/drivers/platform/x86/p2sb.c
> @@ -46,6 +46,10 @@ static int p2sb_get_devfn(unsigned int *devfn)
> unsigned int fn = P2SB_DEVFN_DEFAULT;
> const struct x86_cpu_id *id;
>
> + /* ICH/PCHs for old CPUs do not have P2SB */
> + if (boot_cpu_data.x86 != 6)
> + return -ENODEV;
> +
> id = x86_match_cpu(p2sb_cpu_ids);
> if (id)
> fn = (unsigned int)id->driver_data;
This patch snippet resolves the issue, at least in my use case.
Thanks,
Tested-by: Klara Modin <klarasmodin@xxxxxxxxx>
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