Re: [PATCH v23 1/2] ACPI:RAS2: Add driver for the ACPI RAS2 feature table

On Wed, Aug 12, 2026 at 2:51 AM Ashok Raj <[email protected]> wrote:
>
> Hi Shiju
>
> On Sun, Jul 26, 2026 at 10:28:11PM +0100, [email protected] wrote:
> > From: Shiju Jose <[email protected]>
> >
> > ACPI 6.5 Specification, section 5.2.21, defined RAS2 feature table (RAS2).
> > Driver adds support for RAS2 feature table, which provides interfaces for
> > platform RAS features, e.g., for HW-based memory scrubbing, and logical to
> > PA translation service. RAS2 uses PCC channel subspace for communicating
> > with the ACPI compliant HW platform.
> >
> > Co-developed-by: A Somasundaram <[email protected]>
> > Signed-off-by: A Somasundaram <[email protected]>
> > Co-developed-by: Jonathan Cameron <[email protected]>
> > Signed-off-by: Jonathan Cameron <[email protected]>
> > Tested-by: Daniel Ferguson <[email protected]>
> > Reviewed-by: Ashok Raj <[email protected]>
> > Signed-off-by: Shiju Jose <[email protected]>
> > ---
> >  drivers/acpi/Kconfig  |  11 +
> >  drivers/acpi/Makefile |   1 +
> >  drivers/acpi/bus.c    |   3 +
> >  drivers/acpi/ras2.c   | 509 ++++++++++++++++++++++++++++++++++++++++++
> >  include/acpi/ras2.h   |  57 +++++
> >  5 files changed, 581 insertions(+)
> >  create mode 100644 drivers/acpi/ras2.c
> >  create mode 100644 include/acpi/ras2.h
> >
> > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>
> [snip]
>
> > +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd)
> > +{
> > +     struct acpi_ras2_shmem __iomem *gen_comm_base;
> > +     struct mbox_chan *pcc_channel;
> > +     struct ras2_sspcc *sspcc;
> > +     s64 time_delta;
> > +     u16 val;
> > +     int rc;
> > +
>
> [snip]
>
> > +
> > +     /* Ring doorbell */
> > +     rc = mbox_send_message(pcc_channel, &cmd);
> > +     /*
> > +      * mbox_send_message() returns a non-negative integer for successful submission
> > +      * and a negative value on failure.
> > +      */
> > +     if (rc < 0) {
> > +             dev_warn(ras2_ctx->dev,
> > +                      "Error sending PCC mbox message command: 0x%x, rc:%d\n", cmd, rc);
> > +             /* Restore CMD COMPLETE bit on error */
> > +             val = ioread16(&gen_comm_base->status);
> > +             val |= PCC_STATUS_CMD_COMPLETE;
> > +             iowrite16(val, &gen_comm_base->status);
> > +             return rc;
> > +     } else {
> > +             rc = 0;
> > +     }
>
> Minor:
>
> Sorry, I missed in prior review.
>
> Can the else after return be removed?
> just set rc = 0 should be sufficient.

Hi Ashok,

Thanks for the feedback.
I will make this change if another version is needed.

Thanks,
Shiju

>
> Cheers,
> Ashok