From 008ede54e424e49256106c201e5458551eacf238 Mon Sep 17 00:00:00 2001 From: mstsirkin Date: Mon, 22 Dec 2014 08:56:23 +0000 Subject: ccw: two-stage indicators for legacy devices Some legacy devices will support two-stage queue indicators and therefore won't reject CCW_CMD_SET_IND_ADAPTER. Note this. VIRTIO-127 Signed-off-by: Cornelia Huck Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio/trunk@443 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652 --- content.tex | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/content.tex b/content.tex index d2d9ae7..952b605 100644 --- a/content.tex +++ b/content.tex @@ -2742,8 +2742,11 @@ command reject to any subsequent CCW_CMD_SET_IND_ADAPTER command. \paragraph{Legacy Interfaces: A Note on Setting Up Indicators}\label{sec:Virtio Transport Options / Virtio over channel I/O / Device Initialization / Setting Up Indicators / Legacy Interfaces: A Note on Setting Up Indicators} -Legacy devices will only support classic queue indicators; they will -reject CCW_CMD_SET_IND_ADAPTER as they don't know that command. +In some cases, legacy devices will only support classic queue indicators; +in that case, they will reject CCW_CMD_SET_IND_ADAPTER as they don't know that +command. Some legacy devices will support two-stage queue indicators, though, +and a driver will be able to successfully use CCW_CMD_SET_IND_ADAPTER to set +them up. \subsection{Device Operation}\label{sec:Virtio Transport Options / Virtio over channel I/O / Device Operation} -- cgit v1.2.3