From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Fri, 07 Jul 2023 08:26:48 +0200 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 1qHeva-001CGH-4W for lore@lore.pengutronix.de; Fri, 07 Jul 2023 08:26:48 +0200 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 1qHevX-0004bS-GO for lore@pengutronix.de; Fri, 07 Jul 2023 08:26:48 +0200 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From: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=7yn6fXZrDjQ5hdNtPZ7lTBWOyaeXEcz8WHubEr+AO8s=; b=OCdB5uHF6wGkQFHZm9mNcpAawR CEtI7+2WWSVZQGmam3Bts89wg0L77d6J2CP5NFbVERJO2LpL/JipN2Kk18O+7At4RUU9DkNd0xHjJ 0CFnKyAiFAKFJtoBbOJjugDMB/tVw5GC5HceWU++YmWiZHJkZdvY93W/dlRUHgpxQE+WQ+r7TmZJw qs4DTHpOfitMsO7ZpSwYwwGpaH6gCICOXKNQ0ggLqcCIJWbxCyzt+UtWTvpS4Ihb4wyLZcnpfffQe 5yVuILXp8ERa0O82s9OD4c3keXNJa1lNp9bljQ1ClC0D1BOtLcABA8JthksLDdGWeir5/u5I+3E7+ Pk1/iHFw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qHeu4-003kBm-1z; Fri, 07 Jul 2023 06:25:16 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qHeu1-003kAZ-21 for barebox@lists.infradead.org; Fri, 07 Jul 2023 06:25:15 +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 1qHetu-0004Ei-PO; Fri, 07 Jul 2023 08:25:06 +0200 Received: from mfe by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1qHetu-0006Qj-JD; Fri, 07 Jul 2023 08:25:06 +0200 Date: Fri, 7 Jul 2023 08:25:06 +0200 From: Marco Felsch To: Ahmad Fatoum Cc: barebox@lists.infradead.org Message-ID: <20230707062506.k2f6ectsrhfh7vgc@pengutronix.de> References: <20230706161640.843682-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230706161640.843682-1-a.fatoum@pengutronix.de> User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230706_232513_663402_2287F144 X-CRM114-Status: GOOD ( 17.76 ) 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, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH] ddr: imx8m: add comment and print out prior to first DDRC read 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 23-07-06, Ahmad Fatoum wrote: > If board code low level entry forgets to call imx8m*_early_clock_init > before DRAM setup, write access to DRAM controller will seem to work, > but the first read access will hang the system. > > Make debugging this board bring up mistake easier by adding a debug > print along with a comment. > > Signed-off-by: Ahmad Fatoum Reviewed-by: Marco Felsch > --- > drivers/ddr/imx8m/ddr_init.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/ddr/imx8m/ddr_init.c b/drivers/ddr/imx8m/ddr_init.c > index 944cc3873e0c..9a86280d9c73 100644 > --- a/drivers/ddr/imx8m/ddr_init.c > +++ b/drivers/ddr/imx8m/ddr_init.c > @@ -106,7 +106,11 @@ int imx8m_ddr_init(struct dram_timing_info *dram_timing, > reg32_write(DDRC_RFSHCTL3(0), 0x0000001); > reg32_write(DDRC_PWRCTL(0), 0xa0); > > - /* if ddr type is LPDDR4, do it */ > + pr_debug("checking ddr type\n"); > + /* > + * below is first read, so if boot hangs here, imx8m*_early_clock_init() > + * might not have been called > + */ > tmp = reg32_read(DDRC_MSTR(0)); > if (tmp & (0x1 << 5) && ddrc_type != DDRC_TYPE_MN) > reg32_write(DDRC_DDR_SS_GPR0, 0x01); /* LPDDR4 mode */ > -- > 2.39.2 > > >