Hi Rusty,
On 13 May 2013 08:22, Rusty Russell rusty@rustcorp.com.au wrote:
Pranavkumar Sawargaonkar pranavkumar@linaro.org writes:
Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Signed-off-by: Anup Patel anup.patel@linaro.org
Documentation/virtual/virtio-spec.txt | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
OK, I applied this to the lyx master, with three changes:
Changed "filed" to "field".
Added ", or even acknowledging the feature" after "without initializing virtio queues".
Added an initial point to the Device Initialization section:
- If the VIRTIO_CONSOLE_F_EMERG_WRITE feature is offered, the
emerg_wr field of the configuration can be written at any time. Thus it should work for very early boot debugging output as well as catastophic OS failures (eg. virtio ring corruption).
Thanks for applying this patch. Have you also applied first patch ([PATCH V2 1/3] virtio: console: Add emergency writeonly register to config space) with this? (https://lkml.org/lkml/2013/5/6/169)
Thanks, Rusty.
Thanks, Pranav
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