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

[Oleksandr Andrushchenko <Oleksandr_Andrushchenko@epam.com>]

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@epam.com>
>>>>
>>>> 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@epam.com>
>>>
>>> Reviewed-by: Juergen Gross <jgross@suse.com>
>>
>> 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?

>
>
> Juergen

Thank you,

Oleksandr