renesas/drm.git - libdrm, cloned from git://anongit.freedesktop.org/mesa/drm

Age	Commit message (Collapse)	Author
2007-01-02	linux-core: Make git ignore generated module symbol version files.	Michel Dänzer

Document: virtio-v1.0-csprd01 Number: 3 Date: Tue, 21 Jan 2014 15:09:54 +0530 Link to Mail: https://lists.oasis-open.org/archives/virtio-comment/201401/msg00037.html Commenter name: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Decision: Agreed at meeting 2014-01-28. This patch updates virtio spec lyx for adding emergency write to virtio console. Original patch series related to this is -: http://lkml.org/lkml/2013/5/6/167 Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Proposal: diff --git a/content.tex b/content.tex index 17d1bd7..96645df 100644 --- a/content.tex +++ b/content.tex @@ -3225,6 +3225,9 @@ data and outgoing characters are placed in the transmit queue. \item[VIRTIO_CONSOLE_F_MULTIPORT (1)] Device has support for multiple ports; configuration fields nr_ports and max_nr_ports are valid and control virtqueues will be used. + +\item[VIRTIO_CONSOLE_F_EMERG_WRITE (2)] Device has support for emergency write. + Configuration field emerg_wr is valid. \end{description} \subsection{Device configuration layout}\label{sec:Device Types / Console Device / Device configuration layout} @@ -3235,11 +3238,16 @@ data and outgoing characters are placed in the transmit queue. is set, the maximum number of ports supported by the device can be fetched. + If VIRTIO_CONSOLE_F_EMERG_WRITE is set then the driver can use emergency write + to output a single character without initializing virtio queues, or even + acknowledging the feature. + \begin{lstlisting} struct virtio_console_config { le16 cols; le16 rows; le32 max_nr_ports; + le32 emerg_wr; }; \end{lstlisting} @@ -3250,6 +3258,11 @@ native endian of the guest rather than (necessarily) little-endian. \subsection{Device Initialization}\label{sec:Device Types / Console Device / Device Initialization} \begin{enumerate} +\item 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). + \item If the VIRTIO_CONSOLE_F_SIZE feature is negotiated, the driver can read the console dimensions from the configuration fields.