Date: Wed, 04 Mar 2009 21:03:22 -0700 (MST) From: "M. Warner Losh" <imp@bsdimp.com> To: rnoland@FreeBSD.org Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r189367 - head/sys/dev/pci Message-ID: <20090304.210322.1353606728.imp@bsdimp.com> In-Reply-To: <1236224629.1384.22.camel@widget.2hip.net> References: <1236218572.1384.19.camel@widget.2hip.net> <20090304.194158.1159134197.imp@bsdimp.com> <1236224629.1384.22.camel@widget.2hip.net>
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In message: <1236224629.1384.22.camel@widget.2hip.net>
Robert Noland <rnoland@FreeBSD.org> writes:
: On Wed, 2009-03-04 at 19:41 -0700, M. Warner Losh wrote:
: > In message: <1236218572.1384.19.camel@widget.2hip.net>
: > Robert Noland <rnoland@FreeBSD.org> writes:
: > : On Wed, 2009-03-04 at 13:56 -0700, M. Warner Losh wrote:
: > : > In message: <200903041823.n24INmcc049524@svn.freebsd.org>
: > : > Robert Noland <rnoland@freebsd.org> writes:
: > : > : Author: rnoland
: > : > : Date: Wed Mar 4 18:23:48 2009
: > : > : New Revision: 189367
: > : > : URL: http://svn.freebsd.org/changeset/base/189367
: > : > :
: > : > : Log:
: > : > : Extend the management of PCIM_CMD_INTxDIS.
: > : > :
: > : > : We now explicitly enable INTx during bus_setup_intr() if it is needed.
: > : > : Several of the ata drivers were managing this bit internally. This is
: > : > : better handled in pci and it should work for all drivers now.
: > : > :
: > : > : We also mask INTx during bus_teardown_intr() by setting this bit.
: > : > :
: > : > : Reviewed by: jhb
: > : > : MFC after: 3 days
: > : >
: > : > Note: the INTxDIS bit is new in PCI 3.0, and has no effect on earlier
: > : > devices. This should be highlighted in the comments somewhere...
: > :
: > : It is documented in 2.3 as well, I'm not sure about previous versions of
: > : the spec though.
: >
: > It isn't in 2.2, and even after 2.3 it is "optional".
:
: The bit should be unused if it isn't supported by a given piece of
: hardware. If it doesn't do anything, we are no worse off than before.
: I don't think this will cause any harm, only goodness when it is
: supported.
Yes. I agree. This is just the sort of bit, however, that people
looking for an interrupt storm would latch on to as being just the
ticket... Which is why I suggested a comment...
Warner
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