Re: [PATCH 2/3] ACPI: PCC: add check for platform interrupt

[lihuisong (C)]

在 2022/11/10 18:36, Sudeep Holla 写道:
> On Thu, Nov 10, 2022 at 09:50:33AM +0800, Huisong Li wrote:
> > PCC Operation Region driver senses the completion of command by interrupt
> > way. If platform can not generate an interrupt when a command complete,
> > the caller never gets the desired result. So let's reject the setup of the
> > PCC address space on platform that do not support interrupt mode.
> >
> > Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
> > ---
> >   drivers/acpi/acpi_pcc.c | 47 +++++++++++++++++++++++++----------------
> >   1 file changed, 29 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c
> > index 3e252be047b8..8efd08e469aa 100644
> > --- a/drivers/acpi/acpi_pcc.c
> > +++ b/drivers/acpi/acpi_pcc.c
> > @@ -53,6 +53,7 @@ acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
> >   	struct pcc_data *data;
> >   	struct acpi_pcc_info *ctx = handler_context;
> >   	struct pcc_mbox_chan *pcc_chan;
> > +	static acpi_status ret;
> >   
> >   	data = kzalloc(sizeof(*data), GFP_KERNEL);
> >   	if (!data)
> > @@ -69,23 +70,35 @@ acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
> >   	if (IS_ERR(data->pcc_chan)) {
> >   		pr_err("Failed to find PCC channel for subspace %d\n",
> >   		       ctx->subspace_id);
> > -		kfree(data);
> > -		return AE_NOT_FOUND;
> > +		ret = AE_NOT_FOUND;
> > +		goto request_channel_fail;
> >   	}
> Your patch seems to be not based on the upstream.
> Commit f890157e61b8 ("ACPI: PCC: Release resources on address space setup
> failure path") has addressed it already.
I make this patch based on the commit f890157e61b8.
Here is to unify the relese resources path.
> >   	pcc_chan = data->pcc_chan;
> > +	if (!pcc_chan->mchan->mbox->txdone_irq) {
> > +		pr_err("This channel-%d does not support interrupt.\n",
> > +		       ctx->subspace_id);
> > +		ret = AE_SUPPORT;
> > +		goto request_channel_fail;
> > +	}
> Indeed, I supported only interrupt case and this approach is better than
> checking it in handler atleast until we add support for polling based
> transfers in future(hope that never happens, but you never know)
Yes
>