[SCSI] mpt2sas: Added sysfs support for trace buffer
authorKashyap, Desai <kashyap.desai@lsi.com>
Thu, 17 Jun 2010 08:13:17 +0000 (13:43 +0530)
committerJames Bottomley <James.Bottomley@suse.de>
Tue, 27 Jul 2010 17:02:14 +0000 (12:02 -0500)
commit570c67ac443dab5c46e5744e950f0539724cb65d
treedad14200b33f9c0d24c43886b7a88b2a7bf0f2eb
parent203d65b16cfef448dbfb79f66b672be4511fc6a9
[SCSI] mpt2sas: Added sysfs support for trace buffer

Added support so the diag ring buffer can be pulled via sysfs
Added three new shost attributes: host_trace_buffer,
host_trace_buffer_enable, and host_trace_buffer_size.  The
host_trace_buffer_enable attribute is used to either post or release
the trace buffers.   The host_trace_buffer_size attribute contains
the size of the trace buffer. The host_trace_buffer atttribute contains
a maximum 4KB window of the buffer. In order to read the entire host buffer,
you will need to write the offset to  host_trace_buffer prior to reading
it. release the host buffer, then write the entire host buffer contents to
a file.
In addition to this enhancement, we moved the automatic posting of host buffers
at driver load time to be called prior to port_enable, instead of after.
That way discovery is available in the host buffer.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
drivers/scsi/mpt2sas/mpt2sas_base.c
drivers/scsi/mpt2sas/mpt2sas_base.h
drivers/scsi/mpt2sas/mpt2sas_ctl.c