Date: Tue, 19 Apr 2016 16:26:29 +0100 From: Ruslan Bukin <ruslan.bukin@cl.cam.ac.uk> To: Ian Lepore <ian@freebsd.org> Cc: Ruslan Bukin <br@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r298268 - head/sys/dev/spibus Message-ID: <20160419152629.GA28888@bsdpad.com> In-Reply-To: <1461076899.1232.23.camel@freebsd.org> References: <201604191418.u3JEICrY023254@repo.freebsd.org> <1461076899.1232.23.camel@freebsd.org>
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On Tue, Apr 19, 2016 at 08:41:39AM -0600, Ian Lepore wrote: > On Tue, 2016-04-19 at 14:18 +0000, Ruslan Bukin wrote: > > Author: br > > Date: Tue Apr 19 14:18:12 2016 > > New Revision: 298268 > > URL: https://svnweb.freebsd.org/changeset/base/298268 > > > > Log: > > Add optional chip_select/deselect methods. This is required > > when we want to keep CS asserted for multiple transfers. > > > > This is missing a now-required mechanism to arbitrate ownership of the > bus. If a leaf driver can take over the bus for longer than a single > transfer, then it needs the same kind of logic as the iicbus uses > (well, conceptually the same, it doesn't need the same horrible > implementation). > > I also don't see any default implementation of the new methods, or a > commit that adds the new functionality to all existing SPI controller > drivers. > Thanks, Ian. I just realized we don't require to hold CS for multiple transfers in our hardware. So I reverted this. Ruslan
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