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=-8.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 87E2FC38A24 for ; Thu, 7 May 2020 15:42:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4FCC7207DD for ; Thu, 7 May 2020 15:42:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="JdwcDnTH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4FCC7207DD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=TGu1fQrUcOTae+6Oh9xjP0VGuEVoqX5Iy1ML9tPD7w8=; b=JdwcDnTHoHdYmq1OK/o54b4Yz PCfEC8cUFKT2a3ZQsu7msibI8EHbZdqL4zzPZDp6Aw3scyitZid80mogvlTYVsne9Yewo2EJTXZna Oyc3DWgNrwcXvehRz0eyRkGWLO77fpHAk2CQys4GEdl0GwKy8VAakxbT/fwai+H8FtRuHDpLMQuTh /HReoMcTIvuXGICJkJMhbYYmWimY2yv0CAIgq2g8U1oAjjzCShqrZhRTAZ99ZCiqkcsNCETKzrGM4 aL8+4+WnMsYsVvqdUx+kQVKriBCxbxwHYiaduxtwsdEfuQltQMOFID25wf7Df0ULrGQvNQin/Qt9+ NVyMIBZWw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWifq-0007jd-C5; Thu, 07 May 2020 15:42:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWifm-0007i0-QS for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2020 15:42:56 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 08C801FB; Thu, 7 May 2020 08:42:51 -0700 (PDT) Received: from [10.37.12.53] (unknown [10.37.12.53]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 292293F68F; Thu, 7 May 2020 08:42:48 -0700 (PDT) Subject: Re: [PATCH] memory/samsung: Maybe wrong triming parameter To: Bernard Zhao , Kukjin Kim , Krzysztof Kozlowski , linux-pm@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20200507114514.11589-1-bernard@vivo.com> From: Lukasz Luba Message-ID: <2eeb33f7-1acc-66bb-704a-b724fa0be0a8@arm.com> Date: Thu, 7 May 2020 16:42:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200507114514.11589-1-bernard@vivo.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200507_084254_895925_39EA6C02 X-CRM114-Status: GOOD ( 20.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: opensource.kernel@vivo.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Bernard, On 5/7/20 12:45 PM, Bernard Zhao wrote: > In function create_timings_aligned, all the max is to use > dmc->min_tck->xxx, aligned with val dmc->timings->xxx. > But the dmc->timings->tFAW use dmc->min_tck->tXP? > Maybe this point is wrong parameter useing. > > Signed-off-by: Bernard Zhao > --- > drivers/memory/samsung/exynos5422-dmc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c > index 81a1b1d01683..22a43d662833 100644 > --- a/drivers/memory/samsung/exynos5422-dmc.c > +++ b/drivers/memory/samsung/exynos5422-dmc.c > @@ -1091,7 +1091,7 @@ static int create_timings_aligned(struct exynos5_dmc *dmc, u32 *reg_timing_row, > /* power related timings */ > val = dmc->timings->tFAW / clk_period_ps; > val += dmc->timings->tFAW % clk_period_ps ? 1 : 0; > - val = max(val, dmc->min_tck->tXP); > + val = max(val, dmc->min_tck->tFAW); > reg = &timing_power[0]; > *reg_timing_power |= TIMING_VAL2REG(reg, val); > > Good catch! Indeed this should be a dmc->min_tck->tFAW used for clamping. It didn't show up in testing because the frequency values based on which the 'clk_period_ps' are calculated are sane. Check the dump below: [ 5.458227] DMC: mem tFAW=25000, clk_period_ps=6060 [ 5.461743] DMC: tFAW=5, tXP=2 val=5 [ 5.465273] DMC: mem tFAW=25000, clk_period_ps=4854 [ 5.470101] DMC: tFAW=5, tXP=2 val=6 [ 5.473668] DMC: mem tFAW=25000, clk_period_ps=3636 [ 5.478507] DMC: tFAW=5, tXP=2 val=7 [ 5.482072] DMC: mem tFAW=25000, clk_period_ps=2421 [ 5.486951] DMC: tFAW=5, tXP=2 val=11 [ 5.490531] DMC: mem tFAW=25000, clk_period_ps=1841 [ 5.495439] DMC: tFAW=5, tXP=2 val=14 [ 5.499113] DMC: mem tFAW=25000, clk_period_ps=1579 [ 5.503877] DMC: tFAW=5, tXP=2 val=16 [ 5.507476] DMC: mem tFAW=25000, clk_period_ps=1373 [ 5.512368] DMC: tFAW=5, tXP=2 val=19 [ 5.515968] DMC: mem tFAW=25000, clk_period_ps=1212 [ 5.520826] DMC: tFAW=5, tXP=2 val=21 That's why in the existing configuration it does not harm (the calculated 'val' is always >= 5) the board. But I think this patch should be applied (after small changes in the commit message). @Krzysztof could you have a look on the commit message or take the patch with small adjustment in the description, please? I conditionally give (because of this description): Reviewed-by: Lukasz Luba Thank you Bernard for reporting and fixing this. Regards, Lukasz _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel