On 02/21/2018 10:23 AM, Juergen Gross wrote:
On 21/02/18 09:03, Oleksandr Andrushchenko wrote:
From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Initial handling for Xen bus states: implement
Xen bus state machine for the frontend driver according to
the state diagram and recovery flow from display para-virtualized
protocol: xen/interface/io/displif.h.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
drivers/gpu/drm/xen/xen_drm_front.c | 124 +++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/xen/xen_drm_front.h | 26 ++++++++
2 files changed, 149 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/xen/xen_drm_front.h
diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
index fd372fb464a1..d0306f9d660d 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -24,19 +24,141 @@
#include <xen/interface/io/displif.h>
+#include "xen_drm_front.h"
+
+static void xen_drv_remove_internal(struct xen_drm_front_info *front_info)
+{
+}
+
+static int backend_on_initwait(struct xen_drm_front_info *front_info)
+{
+ return 0;
+}
+
+static int backend_on_connected(struct xen_drm_front_info *front_info)
+{
+ return 0;
+}
+
+static void backend_on_disconnected(struct xen_drm_front_info *front_info)
+{
+ xenbus_switch_state(front_info->xb_dev, XenbusStateInitialising);
+}
+
static void backend_on_changed(struct xenbus_device *xb_dev,
enum xenbus_state backend_state)
{
+ struct xen_drm_front_info *front_info = dev_get_drvdata(&xb_dev->dev);
+ int ret;
+
+ DRM_DEBUG("Backend state is %s, front is %s\n",
+ xenbus_strstate(backend_state),
+ xenbus_strstate(xb_dev->state));
+
+ switch (backend_state) {
+ case XenbusStateReconfiguring:
+ /* fall through */
+ case XenbusStateReconfigured:
+ /* fall through */
+ case XenbusStateInitialised:
+ break;
+
+ case XenbusStateInitialising:
+ /* recovering after backend unexpected closure */
+ backend_on_disconnected(front_info);
+ break;
+
+ case XenbusStateInitWait:
+ /* recovering after backend unexpected closure */
+ backend_on_disconnected(front_info);
+ if (xb_dev->state != XenbusStateInitialising)
+ break;
+
+ ret = backend_on_initwait(front_info);
+ if (ret < 0)
+ xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
+ else
+ xenbus_switch_state(xb_dev, XenbusStateInitialised);
+ break;
+
+ case XenbusStateConnected:
+ if (xb_dev->state != XenbusStateInitialised)
+ break;
+
+ ret = backend_on_connected(front_info);
+ if (ret < 0)
+ xenbus_dev_fatal(xb_dev, ret, "initializing DRM driver");
+ else
+ xenbus_switch_state(xb_dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosing:
+ /*
+ * in this state backend starts freeing resources,
+ * so let it go into closed state, so we can also
+ * remove ours
+ */
+ break;
+
+ case XenbusStateUnknown:
+ /* fall through */
+ case XenbusStateClosed:
+ if (xb_dev->state == XenbusStateClosed)
+ break;
+
+ backend_on_disconnected(front_info);
+ break;
+ }
}
static int xen_drv_probe(struct xenbus_device *xb_dev,
const struct xenbus_device_id *id)
{
- return 0;
+ struct xen_drm_front_info *front_info;
+
+ front_info = devm_kzalloc(&xb_dev->dev,
+ sizeof(*front_info), GFP_KERNEL);
+ if (!front_info) {
+ xenbus_dev_fatal(xb_dev, -ENOMEM, "allocating device memory");
No need for message in case of allocation failure: this is
handled in memory allocation already.
Will remove, thank you
Juergen
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
