Re: [PATCH v2] xen/displif: Protocol version 2

[Jürgen Groß <jgross@xxxxxxxx>]

On 02.07.20 09:59, Oleksandr Andrushchenko wrote:
> On 7/2/20 10:20 AM, Jürgen Groß wrote:
> > On 01.07.20 14:07, Oleksandr Andrushchenko wrote:
> > > On 7/1/20 1:46 PM, Jürgen Groß wrote:
> > > > On 01.07.20 09:19, Oleksandr Andrushchenko wrote:
> > > > > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> > > > >
> > > > > 1. Add protocol version as an integer
> > > > >
> > > > > Version string, which is in fact an integer, is hard to handle in the
> > > > > code that supports different protocol versions. To simplify that
> > > > > also add the version as an integer.
> > > > >
> > > > > 2. Pass buffer offset with XENDISPL_OP_DBUF_CREATE
> > > > >
> > > > > There are cases when display data buffer is created with non-zero
> > > > > offset to the data start. Handle such cases and provide that offset
> > > > > while creating a display buffer.
> > > > >
> > > > > 3. Add XENDISPL_OP_GET_EDID command
> > > > >
> > > > > Add an optional request for reading Extended Display Identification
> > > > > Data (EDID) structure which allows better configuration of the
> > > > > display connectors over the configuration set in XenStore.
> > > > > With this change connectors may have multiple resolutions defined
> > > > > with respect to detailed timing definitions and additional properties
> > > > > normally provided by displays.
> > > > >
> > > > > If this request is not supported by the backend then visible area
> > > > > is defined by the relevant XenStore's "resolution" property.
> > > > >
> > > > > If backend provides extended display identification data (EDID) with
> > > > > XENDISPL_OP_GET_EDID request then EDID values must take precedence
> > > > > over the resolutions defined in XenStore.
> > > > >
> > > > > 4. Bump protocol version to 2.
> > > > >
> > > > > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> > > > Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
> > > Thank you, do you want me to prepare the same for the kernel so
> > >
> > > you have it at hand when the time comes?
> > It should be added to the kernel only when really needed (i.e. a user of
> > the new functionality is showing up).
> We have a patch for that which adds EDID to the existing PV DRM frontend,
>
> so while upstreaming those changes I will also include changes to the protocol
>
> in the kernel series: for that we need the header in Xen tree first, right?
Yes.


Juergen