From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Wed, 15 Oct 2014 00:36:04 +0100 Subject: [PATCH v4 4/6] ARM: rockchip: add basic smp support for rk3288 In-Reply-To: <1453932.GC4UXrUPRz@phil> References: <1413231122-1770-1-git-send-email-kever.yang@rock-chips.com> <1413231122-1770-5-git-send-email-kever.yang@rock-chips.com> <1453932.GC4UXrUPRz@phil> Message-ID: <20141014233604.GG27405@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 14, 2014 at 11:23:40PM +0200, Heiko St?bner wrote: > Am Dienstag, 14. Oktober 2014, 13:24:03 schrieb Doug Anderson: > > Kever, > > > > On Mon, Oct 13, 2014 at 1:12 PM, Kever Yang > wrote: > > > + /* > > > + * We need to soft reset the cpu when we turn off the cpu power > > > domain, + * or else the active processors might be stalled when > > > the individual + * processor is powered down. > > > + */ > > > + if (read_cpuid_part_number() != ARM_CPU_PART_CORTEX_A9) { > > > > I haven't done a full review of this patch, but it seems unlikely that > > your uses of read_cpuid_part_number() and read_cpuid_part() in this > > patch are correct. You use both functions and in both cases compare > > the results to ARM_CPU_PART_CORTEX_A9. > > I think read_cpuid_part() would be the correct one, as it does > > read_cpuid_id() & ARM_CPU_PART_MASK > > which in turn should mask the correct parts of the cpuid to match against > ARM_CPU_PART_CORTEX_A9 [0]. The clue is the deprecated message. Clearly the original author did not even build test their code, or if they did, they ignored the warnings. Either way, that's a fairly worrying issue which raises the question: how well was this code tested in the first place? Note that the above quoted if() evaluates to always-false. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net.