From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 24 Jan 2023 09:30:22 +0100 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pKEhD-000I4G-MC for lore@lore.pengutronix.de; Tue, 24 Jan 2023 09:30:22 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pKEhA-0007no-TM for lore@pengutronix.de; Tue, 24 Jan 2023 09:30:21 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; 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Tue, 24 Jan 2023 09:29:03 +0100 Message-ID: Date: Tue, 24 Jan 2023 09:29:02 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Content-Language: en-US To: John Watts , barebox@lists.infradead.org References: <20230123201817.1084728-1-contact@jookia.org> <20230123201817.1084728-2-contact@jookia.org> From: Ahmad Fatoum In-Reply-To: <20230123201817.1084728-2-contact@jookia.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230124_002904_673280_0914249C X-CRM114-Status: GOOD ( 24.48 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.3 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 2/2] imx6-mmdc: Revert calibration configuration on failure X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) On 23.01.23 21:18, John Watts wrote: > When calibration fails it will clobber the existing configuration, > even if the configuration was working but not ideal. > > Reverting calibration from a known bad value to a possibly good value > gives a better chance of the memory working. > > I've tested this on the Novena board and had good success with it. > U-Boot implements a similar solution in its write level calibration. > > Signed-off-by: John Watts > --- > arch/arm/mach-imx/imx6-mmdc.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/mach-imx/imx6-mmdc.c b/arch/arm/mach-imx/imx6-mmdc.c > index 908771626a..0d50b39566 100644 > --- a/arch/arm/mach-imx/imx6-mmdc.c > +++ b/arch/arm/mach-imx/imx6-mmdc.c > @@ -25,11 +25,18 @@ static bool wlcalib_failed(void __iomem *ips) > > int mmdc_do_write_level_calibration(void) > { > + u32 ldectrl[4] = {0}; Initial value never read back. > u32 esdmisc_val, zq_val; > int errorcount = 0; > u32 val; > u32 ddr_mr1 = 0x4; > > + /* Store current calibration data in case of failure */ > + ldectrl[0] = readl(P0_IPS + MPWLDECTRL0); > + ldectrl[1] = readl(P0_IPS + MPWLDECTRL1); > + ldectrl[2] = readl(P1_IPS + MPWLDECTRL0); > + ldectrl[3] = readl(P1_IPS + MPWLDECTRL1); > + > /* disable DDR logic power down timer */ > val = readl((P0_IPS + MDPDC)); > val &= 0xffff00ff; > @@ -69,8 +76,14 @@ int mmdc_do_write_level_calibration(void) > while (readl(P0_IPS + MPWLGCR) & 0x00000001); > > /* check for any errors on both PHYs */ > - if (wlcalib_failed(P0_IPS) || wlcalib_failed(P1_IPS)) > + if (wlcalib_failed(P0_IPS) || wlcalib_failed(P1_IPS)) { > + pr_debug("Calibration failed, rolling back calibration data\n"); Still you only restore P0 calibration data, even if it succeeded, but P1 failed. Is this intended? > + writel(ldectrl[0], P0_IPS + MPWLDECTRL0); > + writel(ldectrl[1], P0_IPS + MPWLDECTRL1); > + writel(ldectrl[2], P1_IPS + MPWLDECTRL0); > + writel(ldectrl[3], P1_IPS + MPWLDECTRL1); > errorcount++; > + } > > pr_debug("Write leveling calibration completed\n"); > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |