From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63B50C28CF6 for ; Wed, 1 Aug 2018 21:18:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F07F0208A4 for ; Wed, 1 Aug 2018 21:18:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="i9ySjM5Y"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="i9ySjM5Y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F07F0208A4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732117AbeHAXFw (ORCPT ); Wed, 1 Aug 2018 19:05:52 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:41572 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727086AbeHAXFw (ORCPT ); Wed, 1 Aug 2018 19:05:52 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id D134F6035F; Wed, 1 Aug 2018 21:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1533158289; bh=BNgs2bDalqAoy3LlvA//EkzUBvpq5eMFUD3teNi4Bl4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=i9ySjM5YQpFY/FbKilCKBkq94foGUJIOcD0UQzpqQmorSTNjRzUuXrefsVfwzFrqc KjG985GmwTx+IftaT9HU8fv+nhpy44LB4lQcZAFSyLv8bym1tPy6EM4T/R4psAFV64 0vKEK+ldqnj09N0HaWmGaFJ+Od9jGsiRkXC+EhDo= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 26E0F60540; Wed, 1 Aug 2018 21:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1533158289; bh=BNgs2bDalqAoy3LlvA//EkzUBvpq5eMFUD3teNi4Bl4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=i9ySjM5YQpFY/FbKilCKBkq94foGUJIOcD0UQzpqQmorSTNjRzUuXrefsVfwzFrqc KjG985GmwTx+IftaT9HU8fv+nhpy44LB4lQcZAFSyLv8bym1tPy6EM4T/R4psAFV64 0vKEK+ldqnj09N0HaWmGaFJ+Od9jGsiRkXC+EhDo= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 01 Aug 2018 14:18:09 -0700 From: rishabhb@codeaurora.org To: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman , Linux Kernel Mailing List , ckadabi@codeaurora.org, tsoni@codeaurora.org, Vikram Mulukutla , rjwysocki@gmail.com Subject: Re: [PATCH] dd: Invoke one probe retry cycle after every initcall level In-Reply-To: References: <1532035440-7860-1-git-send-email-rishabhb@codeaurora.org> Message-ID: <68b90830d5024ce75a20b017aaf21c05@codeaurora.org> X-Sender: rishabhb@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-07-24 01:24, Rafael J. Wysocki wrote: > On Mon, Jul 23, 2018 at 10:22 PM, wrote: >> On 2018-07-23 04:17, Rafael J. Wysocki wrote: >>> >>> On Thu, Jul 19, 2018 at 11:24 PM, Rishabh Bhatnagar >>> wrote: >>>> >>>> Drivers that are registered at an initcall level may have to >>>> wait until late_init before the probe deferral mechanism can >>>> retry their probe functions. It is possible that their >>>> dependencies were resolved much earlier, in some cases even >>>> before the next initcall level. Invoke one probe retry cycle >>>> at every _sync initcall level, allowing these drivers to be >>>> probed earlier. >>> >>> >>> Can you please say something about the actual use case this is >>> expected to address? >> >> We have a display driver that depends 3 other devices to be >> probed so that it can bring-up the display. Because of dependencies >> not being met the deferral mechanism defers the probes for a later >> time, >> even though the dependencies might be met earlier. With this change >> display can be brought up much earlier. > > OK > > What runlevel brings up the display after the change? > > Thanks, > Rafael After the change the display can come up after device_initcall level itself. The above mentioned 3 devices are probed at 0.503253, 0.505210 and 0.523264 secs. Only the first device is probed successfully. With the current deferral mechanism the devices get probed again after late_initcall at 9.19 and 9.35 secs. So display can only come up after 9.35 secs. With this change the devices are re-probed successfully at 0.60 and 0.613 secs. Therefore display can come just after 0.613 secs. This change helps in overall android bootup as well. -Rishabh