From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 25 Jan 2023 16:49:51 +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 1pKi24-001eD9-Q4 for lore@lore.pengutronix.de; Wed, 25 Jan 2023 16:49:51 +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 1pKi21-0000E6-C9 for lore@pengutronix.de; Wed, 25 Jan 2023 16:49:50 +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:From:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=fxS4H/P95NGpwX/5M7x4m14sYeRFq9pt/eehdonyc7Q=; b=5GiqqB8FaUpmRK8z7vZWQ3Ox/c ii7TdmBjDkBJDXVPq9c+MQTMmq7OrdzjE4oPkzy1cKmlP7IrfajCTONEQgQMyrkW1eTYDmsIlVTzF hN6qthXX9ie+7/RQIcjPkw6zrM4WiWE1H0R9osaHiY5TcEybU1itmdFhJbmLKL3dN+hsSwGzNNfM9 /3Pb9eI7fYrUh94NBfUkkemRZZd5l2keU1RqUFrzp1vCDvvgeWtDWiFJf7E6mhoSNzq4V+6FD9tDT SdmT5mqCDSumks17JeRjsXaOqDTeiXDPFibOfH6fc/6F/Uerhj+pGvjWYecX+Bb9Ad1C4ndr42tmS IupW3WfQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKi0l-007rTk-MH; Wed, 25 Jan 2023 15:48:31 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKi0g-007rTB-Nx for barebox@lists.infradead.org; Wed, 25 Jan 2023 15:48:28 +0000 Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pKi0e-0000AY-Lc; Wed, 25 Jan 2023 16:48:24 +0100 Received: from sha by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1pKi0e-00051Q-E8; Wed, 25 Jan 2023 16:48:24 +0100 Date: Wed, 25 Jan 2023 16:48:24 +0100 To: John Watts Cc: barebox@lists.infradead.org Message-ID: <20230125154824.GD13319@pengutronix.de> References: <20230123201817.1084728-1-contact@jookia.org> <20230124174115.1509216-1-contact@jookia.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230124174115.1509216-1-contact@jookia.org> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) From: Sascha Hauer X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230125_074826_799698_3807DBA8 X-CRM114-Status: GOOD ( 37.13 ) 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=-4.7 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH v2 1/2] imx6-mmdc: Work around ERR050070 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 Wed, Jan 25, 2023 at 04:41:15AM +1100, John Watts wrote: > The MPWLGCR registers clear the error bits before software can read them, > so rely on the MPWLHWERR registers for error reporting instead. > > This errata was announced in 2019 but it seems to apply to all chip revisions. > > U-Boot contains a different workaround where it instead checks the calibration > data for the result 0x001F001F (maximum delay) and flag that as a failure. > I can't find the origin of this workaround but I first saw it in the Novena > source code, though I asked Sean Cross and he suggested it was from Freescale. > > While we're at it, fix the comment implying this code only checks PHY0 in x32 > configuration. This is wrong and misleading. > > Signed-off-by: John Watts > --- > Changes v1 -> v2: > - Added a wall of text explaining what the code does and why > - wlcalib_failed now reads from the ips register correctly > --- > arch/arm/mach-imx/imx6-mmdc.c | 30 +++++++++++++++++++--- > arch/arm/mach-imx/include/mach/imx6-mmdc.h | 1 + > 2 files changed, 27 insertions(+), 4 deletions(-) Applied, thanks Sascha > > diff --git a/arch/arm/mach-imx/imx6-mmdc.c b/arch/arm/mach-imx/imx6-mmdc.c > index 00b8d30d69..45e1b030d3 100644 > --- a/arch/arm/mach-imx/imx6-mmdc.c > +++ b/arch/arm/mach-imx/imx6-mmdc.c > @@ -11,6 +11,30 @@ > #include > #include > > +static bool wlcalib_failed(void __iomem *ips) > +{ > + /* > + * The i.MX 6 reference manual specifies that an MMDC flags reports > + * write calibration errors in the MPWLGCR register's HW_WL_ERR field. > + * > + * ERR050070 specifies that this doesn't work and we should check > + * the MPWLHWERR register instead which reports which write leveling > + * steps succeeded or failed on a per-byte basis. > + * > + * Check each byte to see which steps succeeded. If no steps succeeded > + * then declare the calibration a failure. > + */ > + > + int i; > + > + for (i = 0; i < 4; ++i) { > + if (readb(ips + MPWLHWERR + i) == 0) > + return true; > + } > + > + return false; > +} > + > int mmdc_do_write_level_calibration(void) > { > u32 esdmisc_val, zq_val; > @@ -56,11 +80,9 @@ int mmdc_do_write_level_calibration(void) > /* Upon completion of this process the MMDC de-asserts the MPWLGCR[HW_WL_EN] */ > while (readl(P0_IPS + MPWLGCR) & 0x00000001); > > - /* check for any errors: check both PHYs for x64 configuration, if x32, check only PHY0 */ > - if ((readl(P0_IPS + MPWLGCR) & 0x00000F00) || > - (readl(P1_IPS + MPWLGCR) & 0x00000F00)) { > + /* check for any errors on both PHYs */ > + if (wlcalib_failed(P0_IPS) || wlcalib_failed(P1_IPS)) > errorcount++; > - } > > pr_debug("Write leveling calibration completed\n"); > > diff --git a/arch/arm/mach-imx/include/mach/imx6-mmdc.h b/arch/arm/mach-imx/include/mach/imx6-mmdc.h > index bda20aba17..098ba4f5bf 100644 > --- a/arch/arm/mach-imx/include/mach/imx6-mmdc.h > +++ b/arch/arm/mach-imx/include/mach/imx6-mmdc.h > @@ -18,6 +18,7 @@ > #define MPWLGCR 0x808 > #define MPWLDECTRL0 0x80c > #define MPWLDECTRL1 0x810 > +#define MPWLHWERR 0x878 > #define MPPDCMPR1 0x88c > #define MPSWDAR 0x894 > #define MPRDDLCTL 0x848 > -- > 2.39.0 > > > -- 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 |