From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manikanta Maddireddy Subject: Re: [PATCH 07/12] PCI: tegra: Disable AFI dynamic clock gating Date: Mon, 30 Oct 2017 21:48:56 +0530 Message-ID: <382903eb-a6ab-218f-c1e1-4cb64d2c802e@nvidia.com> References: <1509132569-9398-1-git-send-email-mmaddireddy@nvidia.com> <1509132569-9398-8-git-send-email-mmaddireddy@nvidia.com> <063D6719AE5E284EB5DD2968C1650D6DD00A90B0@AcuExch.aculab.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6DD00A90B0-VkEWCZq2GCInGFn1LkZF6NBPR1lH4CV8@public.gmane.org> Content-Language: en-US Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Laight , "thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org" , "bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org" , "jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org" Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "vidyas-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org" , "kthota-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 30-Oct-17 9:28 PM, David Laight wrote: > From: Manikanta Maddireddy >> Sent: 27 October 2017 20:29 >> When there are 32 outstanding writes from AFI to memory, the outstanding >> write counter overflows and indicates that there are "0" outstanding write >> transactions. This outstanding write counter is used to generate IDLE >> signal to dynamically gate the AFI clock. >> >> When memory controller is under heavy load, its possible that write >> completions will come back to AFI after long delay and AFI write counter >> overflows. AFI clock gets gated even when there are outstanding >> transactions towards memory controller resutling in system hang. >> >> Disable dynamic clock gating of AFI clock to avoid system hang. > > At least some of the above really ought to be comments in the code. > (and with the earlier fix for limiting the number of writes.) > > David > Ok, will take care of it in next version