From mboxrd@z Thu Jan 1 00:00:00 1970 From: mans@mansr.com (=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=) Date: Tue, 03 Nov 2015 10:12:56 +0000 Subject: [PATCH v8 2/2] arm-soc: Add support for arm-based tango4 platforms In-Reply-To: <563871A9.7050009@sigmadesigns.com> (Marc Gonzalez's message of "Tue, 3 Nov 2015 09:34:49 +0100") References: <56377E76.2080209@sigmadesigns.com> <56377F09.6050805@sigmadesigns.com> <20151102182615.GI2684@leverpostej> <5637AD74.4080206@oracle.com> <563871A9.7050009@sigmadesigns.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Marc Gonzalez writes: > Santosh Shilimkar wrote: > >> Mark Rutland wrote: >> >>> We didn't. Having a look just now, the earliest example appears to be >>> in OMAP4 L2 support patches back in 2009 [1]. I was not able to find a >>> rationale. >>> >>> Given that the MMU is on (and speculative accesses are permitted) I >>> can't see what the DSB achieves -- it can't quiesce the memory system. >>> >>> Santosh, any idea? >> >> IIRC, it was requirement from the OMAP ROM code to have a dsb before >> we call the SMC routine. I can't recollect more than that now. > > In that case, shouldn't dsb have been added to the ROM code, > on the "other side" of the smc, so as to not depend on Linux > code "getting it right"? You're new to this, aren't you? :) -- M?ns Rullg?rd mans at mansr.com