[PATCH V2 2/3] Documentation: virtio: Add emergency write (emerg_wr) config register in virtio console.

Pranavkumar Sawargaonkar pranavkumar at linaro.org
Mon May 6 08:19:50 EDT 2013


Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
Signed-off-by: Anup Patel <anup.patel at linaro.org>
---
 Documentation/virtual/virtio-spec.txt |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Documentation/virtual/virtio-spec.txt b/Documentation/virtual/virtio-spec.txt
index 0d6ec85..3ca38f8 100644
--- a/Documentation/virtual/virtio-spec.txt
+++ b/Documentation/virtual/virtio-spec.txt
@@ -1927,11 +1927,16 @@ Ports 2 onwards only if VIRTIO_CONSOLE_F_MULTIPORT is set
     ports; configuration fields nr_ports and max_nr_ports are
     valid and control virtqueues will be used.
 
+  VIRTIO_CONSOLE_F_EMERG_WRITE(2) Device has support for emergency
+  write. Configuration filed emerg_wr is valid.
+
   Device configuration layout The size of the console is supplied
   in the configuration space if the VIRTIO_CONSOLE_F_SIZE feature
   is set. Furthermore, if the VIRTIO_CONSOLE_F_MULTIPORT feature
   is set, the maximum number of ports supported by the device can
-  be fetched.struct virtio_console_config {
+  be fetched. If VIRTIO_CONSOLE_F_EMERG_WRITE is set then one can
+  use emergency write to output single character without initializing
+  virtio queues. struct virtio_console_config {
 
 	u16 cols;
 
@@ -1941,6 +1946,7 @@ Ports 2 onwards only if VIRTIO_CONSOLE_F_MULTIPORT is set
 
 	u32 max_nr_ports;
 
+	u32 emerg_wr;
 };
 
   Device Initialization
-- 
1.7.9.5




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