2021-10-22 07:42:08

by Harris Song

Subject: [PATCH] ACPI: CPPC: fix return value in register_pcc_channel()

It uses IS_ERR to judge the return value of
pcc_mbox_request_channel().If it is invalid, maybe we should
use PTR_ERR to get the correct return value.

Signed-off-by: Kai Song <[email protected]>
---
drivers/acpi/cppc_acpi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index bd482108310c..0bbb5fa27ce7 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -503,7 +503,7 @@ static int register_pcc_channel(int pcc_ss_idx)
if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) {
pr_err("Failed to find PCC channel for subspace %d\n",
pcc_ss_idx);
- return -ENODEV;
+ return PTR_ERR(pcc_data[pcc_ss_idx]->pcc_channel);
}

/*
--
2.27.0

2021-10-22 12:38:59

by Rafael J. Wysocki

Subject: Re: [PATCH] ACPI: CPPC: fix return value in register_pcc_channel()

On Fri, Oct 22, 2021 at 9:39 AM Kai Song <[email protected]> wrote:
>
> It uses IS_ERR to judge the return value of
> pcc_mbox_request_channel().If it is invalid, maybe we should
> use PTR_ERR to get the correct return value.

Either there is a reason to make this change or there isn't.

If there is a reason, then what is it?

> Signed-off-by: Kai Song <[email protected]>
> ---
> drivers/acpi/cppc_acpi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index bd482108310c..0bbb5fa27ce7 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -503,7 +503,7 @@ static int register_pcc_channel(int pcc_ss_idx)
> if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) {
> pr_err("Failed to find PCC channel for subspace %d\n",
> pcc_ss_idx);
> - return -ENODEV;
> + return PTR_ERR(pcc_data[pcc_ss_idx]->pcc_channel);
> }
>
> /*
> --
> 2.27.0
>

2021-10-25 01:29:14

by Harris Song

Subject: 答复: [gmail.com代发]Re: [PATCH] ACPI: CP PC: fix return value in register_pcc_channel( )

> On Fri, Oct 22, 2021 at 9:39 AM Kai Song <[email protected]> wrote:
> >
> > It uses IS_ERR to judge the return value of
> > pcc_mbox_request_channel().If it is invalid, maybe we should use
> > PTR_ERR to get the correct return value.
>
> Either there is a reason to make this change or there isn't.
>
> If there is a reason, then what is it?

Thank you for your reminding, pcc_mbox_request_channel() has other return values like -EBUSY.
But I checked through the context , it seems -ENODEV is ok.

So this patch seems harmless but not needed.
Thank you for your time.

Kai

> > Signed-off-by: Kai Song <[email protected]>
> > ---
> > drivers/acpi/cppc_acpi.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index
> > bd482108310c..0bbb5fa27ce7 100644
> > --- a/drivers/acpi/cppc_acpi.c
> > +++ b/drivers/acpi/cppc_acpi.c
> > @@ -503,7 +503,7 @@ static int register_pcc_channel(int pcc_ss_idx)
> > if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) {
> > pr_err("Failed to find PCC channel for subspace %d\n",
> > pcc_ss_idx);
> > - return -ENODEV;
> > + return
> > + PTR_ERR(pcc_data[pcc_ss_idx]->pcc_channel);
> > }
> >
> > /*
> > --
> > 2.27.0
> >