Re: [EXT] Re: [PATCH 04/14] cxl/mem: Implement polled mode mailbox

Ben Widawsky
2021-02-04T22:25:26Z

On 21-02-04 21:53:29, John Groves (jgroves) wrote:
> Micron Confidential
>
>
>
> From: Dan Williams <dan.j.williams@intel.com>
> Date: Monday, February 1, 2021 at 1:28 PM
> To: Ben Widawsky <ben.widawsky@intel.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
> linux-cxl@vger.kernel.org <linux-cxl@vger.kernel.org>, Linux ACPI
> <linux-acpi@vger.kernel.org>, Linux Kernel Mailing List
> <linux-kernel@vger.kernel.org>, linux-nvdimm
> <linux-nvdimm@lists.01.org>, Linux PCI <linux-pci@vger.kernel.org>,
> Bjorn Helgaas <helgaas@kernel.org>, Chris Browy
> <cbrowy@avery-design.com>, Christoph Hellwig <hch@infradead.org>, Ira
> Weiny <ira.weiny@intel.com>, Jon Masters <jcm@jonmasters.org>, Jonathan
> Cameron <Jonathan.Cameron@huawei.com>, Rafael Wysocki
> <rafael.j.wysocki@intel.com>, Randy Dunlap <rdunlap@infradead.org>,
> Vishal Verma <vishal.l.verma@intel.com>, daniel.lll@alibaba-inc.com
> <daniel.lll@alibaba-inc.com>, John Groves (jgroves)
> <jgroves@micron.com>, Kelley, Sean V <sean.v.kelley@intel.com>
> Subject: [EXT] Re: [PATCH 04/14] cxl/mem: Implement polled mode mailbox
>
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> On Mon, Feb 1, 2021 at 11:13 AM Ben Widawsky <ben.widawsky@intel.com>
> wrote:
> >
> > On 21-02-01 12:54:00, Konrad Rzeszutek Wilk wrote:
> > > > +#define
> cxl_doorbell_busy(cxlm)
> \
> > > > + (cxl_read_mbox_reg32(cxlm, CXLDEV_MB_CTRL_OFFSET)
> & \
> > > > + CXLDEV_MB_CTRL_DOORBELL)
> > > > +
> > > > +#define CXL_MAILBOX_TIMEOUT_US 2000
> > >
> > > You been using the spec for the values. Is that number also from it
> ?
> > >
> >
> > Yes it is. I'll add a comment with the spec reference.
>
>
>
> From section 8.2.8.4 in the CXL 2.0 spec: “The mailbox command timeout
> is 2 seconds.” So this should be:
>
>
> #define CXL_MAILBOX_TIMEOUT_US 2000000
>
>
> …right? 2000us is 2ms…
>
>

Thanks. This was caught already in earlier review by David Rientjes
<rientjes@google.com>

It's renamed CXL_MAILBOX_TIMEOUT_MS 2000