From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 10 Apr 2015 22:57:48 +0200 Subject: [RFC PATCH v2 4/4] arm64: qcom: add cpu operations In-Reply-To: <1428698605-13166-5-git-send-email-galak@codeaurora.org> References: <1428698605-13166-1-git-send-email-galak@codeaurora.org> <1428698605-13166-5-git-send-email-galak@codeaurora.org> Message-ID: <5280857.52XJYGkVLd@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 10 April 2015 15:43:25 Kumar Gala wrote: > +static int qcom_cpu_boot(unsigned int cpu) > +{ > + int ret = 0; > + > + if (per_cpu(cold_boot_done, cpu) == false) { > + ret = qcom_unclamp_secondary_arm_cpu(cpu); > + if (ret) > + return ret; > + per_cpu(cold_boot_done, cpu) = true; > + } > + return secondary_pen_release(cpu); > +} > + Please add a comment here to explain why you need a two-stage process here, rather than just booting the CPU without the secondary_pen. Are you working around a specific silicon bug here? Arnd