Re: [PATCH 4/6] xen: Sync up with the canonical protocol definition in Xen

2020-08-04 Thread Jürgen Groß

On 31.07.20 14:51, Oleksandr Andrushchenko wrote:

From: Oleksandr Andrushchenko 

This is the sync up with the canonical definition of the
display protocol in Xen.

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 


Reviewed-by: Juergen Gross 


Juergen


[PATCH 4/6] xen: Sync up with the canonical protocol definition in Xen

2020-07-31 Thread Oleksandr Andrushchenko
From: Oleksandr Andrushchenko 

This is the sync up with the canonical definition of the
display protocol in Xen.

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 
---
 include/xen/interface/io/displif.h | 91 +-
 1 file changed, 88 insertions(+), 3 deletions(-)

diff --git a/include/xen/interface/io/displif.h 
b/include/xen/interface/io/displif.h
index fdc279dc4a88..c2d900186883 100644
--- a/include/xen/interface/io/displif.h
+++ b/include/xen/interface/io/displif.h
@@ -38,7 +38,8 @@
  *   Protocol version
  **
  */
-#define XENDISPL_PROTOCOL_VERSION  "1"
+#define XENDISPL_PROTOCOL_VERSION  "2"
+#define XENDISPL_PROTOCOL_VERSION_INT   2
 
 /*
  **
@@ -202,6 +203,9 @@
  *  Width and height of the connector in pixels separated by
  *  XENDISPL_RESOLUTION_SEPARATOR. This defines visible area of the
  *  display.
+ *  If backend provides extended display identification data (EDID) with
+ *  XENDISPL_OP_GET_EDID request then EDID values must take precedence
+ *  over the resolutions defined here.
  *
  *-- Connector Request Transport Parameters ---
  *
@@ -349,6 +353,8 @@
 #define XENDISPL_OP_FB_DETACH  0x13
 #define XENDISPL_OP_SET_CONFIG 0x14
 #define XENDISPL_OP_PG_FLIP0x15
+/* The below command is available in protocol version 2 and above. */
+#define XENDISPL_OP_GET_EDID   0x16
 
 /*
  **
@@ -377,6 +383,10 @@
 #define XENDISPL_FIELD_BE_ALLOC"be-alloc"
 #define XENDISPL_FIELD_UNIQUE_ID   "unique-id"
 
+#define XENDISPL_EDID_BLOCK_SIZE   128
+#define XENDISPL_EDID_BLOCK_COUNT  256
+#define XENDISPL_EDID_MAX_SIZE (XENDISPL_EDID_BLOCK_SIZE * 
XENDISPL_EDID_BLOCK_COUNT)
+
 /*
  **
  *  STATUS RETURN CODES
@@ -451,7 +461,9 @@
  * +++++
  * |   gref_directory  | 40
  * +++++
- * | reserved  | 44
+ * | data_ofs  | 44
+ * +++++
+ * | reserved  | 48
  * +++++
  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
  * +++++
@@ -494,6 +506,7 @@
  *   buffer size (buffer_sz) exceeds what can be addressed by this single page,
  *   then reference to the next page must be supplied (see gref_dir_next_page
  *   below)
+ * data_ofs - uint32_t, offset of the data in the buffer, octets
  */
 
 #define XENDISPL_DBUF_FLG_REQ_ALLOC(1 << 0)
@@ -506,6 +519,7 @@ struct xendispl_dbuf_create_req {
uint32_t buffer_sz;
uint32_t flags;
grant_ref_t gref_directory;
+   uint32_t data_ofs;
 };
 
 /*
@@ -731,6 +745,44 @@ struct xendispl_page_flip_req {
uint64_t fb_cookie;
 };
 
+/*
+ * Request EDID - request EDID describing current connector:
+ * 01 2   3octet
+ * +++++
+ * |   id| _OP_GET_EDID   |   reserved | 4
+ *